CN114075065A - Fractured formation chemical wall-fixing agent, preparation method and application thereof, and advanced injection construction method - Google Patents
Fractured formation chemical wall-fixing agent, preparation method and application thereof, and advanced injection construction method Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
- E21B33/138—Plastering the borehole wall; Injecting into the formation
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/24—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
- C04B28/26—Silicates of the alkali metals
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/42—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells
- C09K8/46—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells containing inorganic binders, e.g. Portland cement
- C09K8/467—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells containing inorganic binders, e.g. Portland cement containing additives for specific purposes
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00732—Uses not provided for elsewhere in C04B2111/00 for soil stabilisation
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/12—Swell inhibition, i.e. using additives to drilling or well treatment fluids for inhibiting clay or shale swelling or disintegrating
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Abstract
The invention discloses a chemical wall-fixing agent for a fractured formation, a preparation method and application thereof, and an advanced injection construction method. The chemical wall-solidifying agent comprises slag, bentonite, water glass, gypsum and superfine calcite. The advanced injection construction method comprises the following steps: adding a packer at the upper part close to the drill bit; carrying out deep fractured formation pre-drilling prediction; uncovering the proper depth of the broken zone, and injecting the chemical wall-fixing agent in advance; displacing the chemical wall-fixating agent into the formation; waiting for coagulation; the broken belt is torn off by drilling. According to the method, the chemical wall-fixing agent is injected into the fractured stratum in advance, so that the mechanical strength of the rock mass is integrally improved, the stability of the well wall of the long open hole section is improved, the risks of jamming and burying of the drill are obviously reduced, and the method is a method for greatly improving the stability of the well wall of the deep fractured stratum.
Description
Technical Field
The invention relates to the field of petroleum and natural gas drilling, in particular to a chemical wall-fixing agent for a fractured formation, a preparation method and application thereof, and an advanced injection construction method, which are used for strengthening the stability of a well wall of drilling fluid for the fractured formation.
Background
With the continuous expansion of global energy consumption, conventional oil and gas resources cannot meet the increasing world energy demand, and the target layer of oil and gas exploration and development rapidly extends from the middle shallow layer to the deep stratum. Since the global deep ultra-deep layer oil and gas resources are very abundant, since Carter-Knox oil and gas fields are found below 4500m in the United states in 1952, more than 1000 oil and gas fields buried below 4500m have been successfully developed globally until now. In 2018, the external dependence of oil and gas in China is respectively increased to 66.67% and 45.30%, and 70% of residual oil and gas resources in China are not effectively developed in deep strata. In order to accelerate the promotion of energy production and consumption revolution of China and enhance the autonomous guarantee capability of energy safety, the development of deep oil and gas resources is imperative. In recent years, significant oil and gas breakthrough is obtained along with the field of Tarim basin carbonate rock and Sichuan basin deep sea phase carbonate rock. Deep oil and gas reservoirs gradually become the field of oil and gas resources which have practical exploration and development significance in China. However, deep hydrocarbon reservoirs are characterized by special geological conditions and complex ground stress conditions, and damage zones with different damage degrees, namely fractured formations, are usually developed in deep formations under the action of long time, multiple times, strong tectonic movement and high ground stress. The problem of deep fractured formation well wall instability is prominent under the action of high temperature, high pressure, high ground stress and high disturbance stress in the drilling process. Taking the northward oil-gas field as an example (see table 1), when the Ordovician carbonate rock broken stratum is drilled in the oil-gas field construction process, the block is seriously fallen, and the drilling time efficiency is seriously influenced. According to incomplete statistics, the 5 exploration evaluation wells drilled in a work area are drilled on the same side for more than 10 times due to serious collapse and block falling of the well wall, the loss time of a single well reaches 242d at most, the accumulated loss time exceeds 669d, and the period of processing the shaft accounts for 48.2% of the total period of drilling at most.
TABLE 1 northward block drilling complexity and disposal time
It can be seen that the problem of borehole instability of deep fractured carbonate hydrocarbon reservoirs becomes a prominent problem which restricts the efficient well construction of such reservoirs. In the practice of comprehensive field drilling, the instability of the borehole wall of the fractured layer is represented as follows: firstly, obvious well wall dropping blocks occur just after the stratum is uncovered; secondly, the drilling fluid density is improved in the drilling process, so that the instability of the well wall can be relieved to a certain extent, but leakage occurs for many times. Analysis shows that the deep fractured rock stratum is subjected to construction application in the past, natural cracks of the stratum develop, and the rock mass strength is low. The instability of the uncovered stratum is mainly caused by the low strength of rock mass and the common storage of larger strain energy, so when the stratum is just uncovered, the strain energy is released due to the insufficient strength of rock; the leakage caused by the increase of the density of the drilling fluid is mainly caused by the fact that the rock mass of the fractured stratum has low strength and poor pressure bearing capacity, and the increase of the density of the drilling fluid is easy to exceed the pressure bearing capacity of the stratum, thus causing leakage. Therefore, the key for controlling the well wall stability of the deep fractured stratum is to properly improve the rock strength before drilling and uncovering the stratum as much as possible, so that the effects of inhibiting the stress release of the stratum and improving the pressure bearing capacity of the stratum are achieved.
The chemical consolidation leakage-stopping technique is a common leakage-stopping method for raising the strength of unconsolidated stratum and fractured-vuggy stratum. When the consolidation plugging method is adopted, the size of a leakage passage does not need to be considered, the solidification time adjustment range of the consolidation plugging slurry is large, the percolation capacity of the slurry is strong, the filtrate can be solidified, and the success rate is high. At present, the mature chemical consolidation plugging technology is mainly carried out aiming at uncovering a stratum, namely after the uncovering stratum has leakage, drilling with drilling plugging slurry to uncover a leakage stratum section, and then carrying out chemical consolidation special plugging operation on a leakage point. However, at present, the thickness of a deep fractured stratum layer is large, a part of well types are even designed into horizontal well types, and the drilling fractured layer section is long. If the conventional strong drilling is adopted for chemical consolidation and leakage stoppage, a large amount of slurry for leakage stoppage along with drilling is wasted, the time efficiency of pure drilling is reduced, and the risks of drill sticking and drill burying are increased. Therefore, the chemical wall-fixing agent for the fractured formation, the preparation method thereof and the advanced injection construction method are provided, and the rock strength of the deep fractured volatile stable formation is improved in advance and in a large range so as to relieve the problem of borehole wall instability.
Disclosure of Invention
In view of the current thick big deep fragmentity stratum layer, some well types even design for horizontal well type, bore and meet fragmentity stratum section length. If the conventional strong drilling is adopted for chemical consolidation and leaking stoppage, a large amount of slurry for leaking stoppage along with drilling is wasted, the time efficiency of pure drilling is reduced, and the risks of drill sticking, even drill burying and the like are increased. The invention provides a chemical wall-fixing agent for a fractured stratum, a preparation method thereof and an advanced injection construction method.
One of the purposes of the invention is to provide a chemical wall-fixing agent for a fragmental stratum, which comprises slag, bentonite, water glass, gypsum and superfine calcite.
The chemical wall-fixing agent also comprises water.
The chemical wall-solidifying agent comprises water, slag, bentonite, water glass, gypsum and superfine calcite, wherein the slag accounts for 10-20 parts by weight, the bentonite accounts for 3-10 parts by weight, the water glass accounts for 3-10 parts by weight, the gypsum accounts for 0.5-1.5 parts by weight, and the superfine calcite accounts for 2-12 parts by weight based on 100 parts by weight of water.
Preferably, the slag is 15 to 20 parts by weight, the bentonite is 3 to 5 parts by weight, the water glass is 3 to 6 parts by weight, the gypsum is 0.5 to 1 part by weight, and the ultrafine calcite is 2 to 10 parts by weight, based on 100 parts by weight of water.
The particle size of the slag and the superfine calcite particles is far smaller than the width of a natural crack of a stratum, preferably, the particle size of the slag is smaller than 50 micrometers, and more preferably 10-30 micrometers;
preferably, the particle size of the superfine calcite is less than 30 μm, and more preferably 5-25 μm.
The modulus of the water glass is 1.5-3.5, and the concentration of the water glass is 30-43 Be; preferably, the modulus of the water glass is 1.5-3.0, and the concentration of the water glass is 35-43 Be.
Compared with the solid-phase granularity of the existing chemical consolidation agent, the solid-phase granularity of the chemical wall consolidation agent is finer, and the chemical wall consolidation agent can invade into the deep part of a rock crack under smaller displacement pressure.
The other purpose of the invention is to provide a preparation method of the chemical wall-fixing agent for the fractured formation, which comprises the step of uniformly mixing components including slag, bentonite, water glass, gypsum and superfine calcite.
Preferably, the preparation method comprises adding slag, bentonite, water glass, gypsum and ultrafine calcite particles into water, and uniformly mixing.
More preferably, the preparation method of the fractured formation chemical wall-fixing agent can comprise the following steps: under the stirring condition, 10-20 parts by weight of slag, 3-10 parts by weight of bentonite, 3-10 parts by weight of water glass, 0.5-1.5 parts by weight of gypsum and 2-12 parts by weight of ultrafine calcite particles are added into 100 parts by weight of water, and the materials are fully stirred until the materials are uniformly mixed.
Most preferably, the preparation method may comprise the steps of: under the stirring condition, adding 15-20 parts by weight of slag, 3-5 parts by weight of bentonite, 3-6 parts by weight of water glass, 0.5-1 part by weight of gypsum and 2-10 parts by weight of ultrafine calcite particles into 100 parts by weight of water, and fully stirring until the materials are uniformly mixed.
The invention also aims to provide the application of the chemical wall-fixing agent for the fractured formation in the drilling of oil and natural gas.
The chemical wall-fixing agent for the fractured formation can improve the stability of the well wall of the deep fractured formation.
The fourth purpose of the invention is to provide a construction method for injecting the chemical wall-fixing agent into the fractured formation ahead of time, which comprises the step of injecting the chemical wall-fixing agent into the fractured formation after uncovering the fractured zone to a proper depth until the chemical wall-fixing agent is solidified.
In the method, the deep fractured formation pre-drilling prediction is carried out before the chemical wall-fixing agent is injected in advance, the proper depth for uncovering the fractured formation is determined according to the prediction result, and then the chemical wall-fixing agent is injected.
Preferably, the construction method for the advanced injection of the chemical wall-fixing agent for the fractured formation comprises the following steps:
(1) adding a packer at the upper part close to the drill bit;
(2) carrying out deep fractured formation pre-drilling prediction;
(3) uncovering the proper depth of the broken zone, and injecting the chemical wall-fixing agent in advance;
(4) displacing the chemical wall-fixating agent into the formation;
(5) waiting for coagulation;
(6) the broken belt is torn off by drilling.
In the construction method of the present invention, deep fractured formation geological prediction may be performed before the step (1).
According to a preferred embodiment of the present invention, in the construction method for injecting the chemical wall-fixing agent in advance, the steps may be respectively:
in step (1'), deep fractured formation geology prediction: predicting the breaking characteristics of the drilled and uncovered stratum by using seismic data and adjacent well logging, analyzing the development characteristics of stratum cracks, and determining the high risk layer section of the borehole wall instability; and/or the presence of a gas in the gas,
in the step (1), the drilling tool assembly is replaced: before the breakable stratum section is drilled, a packer is added near the upper part of the drill bit; and/or the presence of a gas in the gas,
in the step (2), predicting the deep fractured stratum before drilling: comprehensively utilizing logging rock debris and drilling parameter changes, predicting a crack development stratum in time, evaluating a stratum well wall instability risk, and performing advanced injection of a chemical wall-fixing agent when the well wall instability risk is large; and/or the presence of a gas in the gas,
in the step (3), the broken stratum is properly uncovered, a certain volume of high-specific gravity chemical wall-fixing agent slurry is prepared on site and is quickly injected into the shaft, the liquid level height of the chemical wall-fixing agent slurry is calculated, and the drill bit is timely lifted to a position of 10-20 m of the chemical wall-fixing agent slurry after the chemical wall-fixing agent slurry is injected; and/or the presence of a gas in the gas,
in the step (4), the drill bit is kept stand, the small-cycle drilling fluid is used for 15-30 min, then the packer is opened, the pressure of the vertical pipe is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, and the chemical wall-fixing agent is guaranteed to invade the stratum; and/or the presence of a gas in the gas,
in the step (5), after the chemical wall-fixing agent slurry completely invades the stratum, the pressure is released, the packer is closed, the drill bit is lifted to 50-100 m above the bottom of the well, and the mixture is kept stand for 4-16 h to wait for the chemical wall-fixing agent slurry to be solidified; and/or the presence of a gas in the gas,
and (6) after the coagulation is finished, lowering a drill bit for plugging, and continuing drilling.
The packer comprises but is not limited to one of a multi-stage ball throwing packer, a multi-stage expanding packer and a multi-stage sliding sleeve packer, can be repeatedly opened and closed for many times, and has stable performance under high temperature and high pressure.
The chemical wall-fixing agent can also comprise but is not limited to a high-strength cement consolidation material, has good fluidity at high temperature and high pressure before thickening, and has strictly controlled solid-phase particle size, and the solid-phase particle size distribution D90 is far smaller than the width of a formation fracture.
Compared with the prior art, the deep fragmenting well wall stabilizing method for injecting the chemical solid wall agent in advance has the following advantages:
(1) by additionally arranging the packer on the upper part of the drill bit, the liquid column pressure close to the drill bit can be effectively improved, the displacement pressure is provided for the chemical wall-fixing agent to continuously invade the stratum, and the deeper invasion depth of the chemical wall-fixing agent is ensured;
(2) by adding the packer which can be repeatedly opened and closed, the drilling tool combination can be prevented from being replaced by drilling when the chemical consolidation plugging is carried out every time, and the construction time is obviously shortened;
(3) the chemical wall-fixing agent is injected in advance, so that the mechanical strength of the rock in the fractured stratum can be obviously improved, the serious borehole wall instability phenomenon on the upper part of the fractured stratum during drilling and uncovering can be prevented, the change degree of the stress around the well is weakened, and the borehole wall instability problem is prevented from being further aggravated;
(4) the chemical wall-fixing agent is injected in advance, so that the mechanical strength of the rock in the fractured stratum can be obviously improved, the strong drilling link of the fractured stratum is reduced, and the drilling jamming and burying risks are obviously reduced.
The invention has the beneficial effects that:
(1) the invention provides an advanced injection chemical wall-fixing agent, a preparation method and a construction method, which are characterized in that the actual conditions that a large amount of drilling leakage-stopping slurry is wasted, the pure drilling time efficiency is reduced, and the risk of drilling jamming and burying is increased if a long-section deep fractured stratum is uncovered by adopting a conventional strong drilling post-chemical consolidation leakage-stopping drill are considered, the chemical wall-fixing agent with a proper invasion depth in a natural crack of the stratum is formed through an unconventional technical idea of advanced injection, the mechanical strength of the rock of the fractured stratum can be obviously improved by injecting the chemical wall-fixing agent as early as possible when the fractured stratum is uncovered as shallow as possible, and the risk of instability of a well wall of the fractured stratum is greatly reduced.
(2) The advanced injection chemical wall-fixing agent is easy to prepare, the curing time is adjustable, the advanced injection chemical wall-fixing agent can moderately invade a fracture stratum, the strength of the fracture stratum is effectively improved, the construction process is clear, only a packer needs to be added to the upper portion of a drill bit during construction, and the operation is simple.
Drawings
FIG. 1 is a schematic diagram showing the development of a drill bit and a nearby formation fracture before a fractured formation is drilled and torn off in the construction process of the well wall stabilizing method for injecting the chemical wall-fixing agent in advance provided by the invention.
FIG. 2 is a schematic diagram showing the development of the drill bit and the cracks in the adjacent stratum during drilling and uncovering of the shallow fractured stratum in the construction process of the well wall stabilizing method for injecting the chemical wall-fixing agent in advance provided by the invention.
FIG. 3 is a schematic diagram showing the development of a drill bit and a nearby formation fracture when a packer is opened to inject a chemical wall-fixing agent in the construction process of the well wall stabilizing method for injecting the chemical wall-fixing agent ahead of time provided by the invention.
FIG. 4 is a schematic diagram showing the development of the drill bit and the cracks in the adjacent stratum during the re-drilling and uncovering of the fractured stratum in the construction process of the well wall stabilizing method for injecting the chemical wall-fixing agent in advance provided by the invention.
Fig. 1-4 label illustrate:
1. a drill stem; 2. a packer; 3. a drill bit; 4. natural fractures of the formation development; 5. and (4) forming a formation fracture after the chemical wall-fixing agent is injected.
FIG. 5 shows the variation of uniaxial compressive strength of rock.
Detailed Description
While the present invention will be described in detail with reference to the following examples, it should be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the present invention.
The starting materials used in the embodiments of the present invention are commercially available.
Example 1
30g of bentonite is added into 1000g of tap water, 100g of slag (the particle size of the slag is less than 38 mu m) and 30g of water glass (the modulus is 1.5, and the concentration is 35Be) are added after stirring for 10 minutes under the environment of 4000 rpm, 5g of gypsum is added after stirring for 10 minutes under the environment of 4000 rpm, 20g of ultrafine calcite particles (the particle size is less than 25 mu m) are added after stirring for 10 minutes under the environment of 4000 rpm, and the chemical wall-solidifying agent A1 is obtained after continuously stirring for 10 minutes.
A high-pressure displacement device and a triaxial rock mechanics test are adopted to simulate a chemical wall-fixing agent advanced injection construction method, namely, a packer is opened, the pressure of a riser is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, the chemical wall-fixing agent is guaranteed to invade a stratum, namely, the chemical wall-fixing agent is injected into loose sandstone with the diameter of 2.54cm multiplied by the length of 5cm through the high-pressure displacement device, the main peak of the pore space diameter of the loose sandstone is 50-70 mu m, the time of the chemical wall-fixing agent penetrating a rock sample and the change of the uniaxial compressive strength of the rock sample are measured, and the test results are shown in Table 2 and figure 5.
Example 2
40g of bentonite is added into 1000g of tap water, 175g of slag (the particle size of the slag is less than 38 mu m) and 60g of water glass (the modulus is 1.5 and the concentration is 35Be) are added after stirring for 10 minutes under the environment of 4000 rpm, 10g of gypsum is added after stirring for 10 minutes under the environment of 4000 rpm, 60g of ultrafine calcite particles (the particle size is less than 13 mu m) are added after stirring for 10 minutes under the environment of 4000 rpm, and the chemical wall-solidifying agent A2 is obtained after continuous stirring for 10 minutes.
A high-pressure displacement device and a triaxial rock mechanics test are adopted to simulate a chemical wall-fixing agent advanced injection construction method, namely, a packer is opened, the pressure of a riser is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, the chemical wall-fixing agent is guaranteed to invade a stratum, namely, the chemical wall-fixing agent is injected into loose sandstone with the diameter of 2.54cm multiplied by the length of 5cm through the high-pressure displacement device, the main peak of the pore space diameter of the loose sandstone is 50-70 mu m, the time of the chemical wall-fixing agent penetrating a rock sample and the change of the uniaxial compressive strength of the rock sample are measured, and the test results are shown in Table 2 and figure 5.
Example 3
Adding 50g of bentonite into 1000g of tap water, stirring for 10 minutes under the environment of the stirring speed of 4000 revolutions per minute, then adding 200g of slag (the particle size of the slag is less than 25 mu m) and 50g of water glass (the modulus is 1.5 and the concentration is 35Be), stirring for 10 minutes under the environment of the stirring speed of 4000 revolutions per minute, then adding 10g of gypsum, stirring for 10 minutes under the environment of the stirring speed of 4000 revolutions per minute, then adding 100g of ultrafine calcite particles (the particle size is less than 13 mu m), and continuously stirring for 10 minutes to obtain the chemical wall-solidifying agent A3.
A high-pressure displacement device and a triaxial rock mechanics test are adopted to simulate a chemical wall-fixing agent advanced injection construction method, namely, a packer is opened, the pressure of a riser is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, the chemical wall-fixing agent is guaranteed to invade a stratum, namely, the chemical wall-fixing agent is injected into loose sandstone with the diameter of 2.54cm multiplied by the length of 5cm through the high-pressure displacement device, the main peak of the pore space diameter of the loose sandstone is 50-70 mu m, the time of the chemical wall-fixing agent penetrating a rock sample and the change of the uniaxial compressive strength of the rock sample are measured, and the test results are shown in Table 2 and figure 5.
Comparative example 1
The comparative example adopts the chemical consolidation plugging agent obtained by the preparation method of the invention patent CN104045271A 'the plugging agent for oil field or natural gas exploitation and the preparation method thereof'. 0.2g of total amount of carboxyl ethylidene diphosphonic acid is put into tap water and stirred evenly; putting 5 parts by weight of 52.5 type portland cement, 11 parts by weight of fine slag with the particle size of below 50 μm, 1 part by weight of bentonite and 1 part by weight of dihydrate gypsum into a stirrer, stirring uniformly, and adding into tap water; is prepared into the product with the density of 1.3g/cm3The solution of (1).
A high-pressure displacement device and a triaxial rock mechanics test are adopted to simulate a chemical wall-fixing agent advanced injection construction method, namely, a packer is opened, the pressure of a riser is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, the chemical wall-fixing agent is guaranteed to invade a stratum, namely, the chemical wall-fixing agent is injected into loose sandstone with the diameter of 2.54cm multiplied by the length of 5cm through the high-pressure displacement device, the main peak of the pore space diameter of the loose sandstone is 50-70 mu m, the time of the chemical wall-fixing agent penetrating a rock sample and the change of the uniaxial compressive strength of the rock sample are measured, and the test results are shown in Table 2 and figure 5.
Example 4
The advanced injection construction method of the chemical wall-fixing agent for the fractured formation of the typical ultra-deep well of the Chinese Tarim basin comprises the following steps:
(1) and (3) carrying out deep fractured stratum geological prediction based on the TARIM-1 well seismic information: predicting the fracture characteristics of the drilled and uncovered stratum by using seismic data and logging of an adjacent well, analyzing the development characteristics of the stratum fracture, and determining that the high risk layer section of borehole wall instability is 6500-6750 m, and the width of the stratum fracture is 100-200 mu m;
(2) drilling to 6490m, pulling out the drill and replacing the drill tool assembly, namely adding a sealing packer at the upper part close to the drill bit before drilling and uncovering the fractured stratum;
(3) drilling and uncovering to break the stratum to 6505m, and preparing 50m in situ according to the prediction result of the width of the stratum fracture3The chemical solid wall slurry is quickly injected into the shaft, and the formula of the chemical solid wall slurry is as follows: adding 50Kg of bentonite into 1000Kg of tap water, and adding 200Kg of slag (slag particle size less than 25 μm) under stirring) And 500Kg of water glass (the modulus is 1.5, the concentration is 35Be), 10Kg of gypsum is added after stirring for 10 minutes under the stirring environment, 100Kg of superfine calcite particles (the particle size is less than 13 mu m) are added after stirring for 10 minutes under the stirring environment, and the chemical wall-fixing agent is obtained after continuously stirring for 10 minutes.
(4) Calculating the liquid level height of the chemical solid wall slurry to be 6450m, and timely lifting the drill bit to a position 10 m-20 m away from the top end of the chemical solid wall slurry after the chemical solid wall slurry is injected, namely a well depth of 6440-6430 m;
(5) standing the drill bit, and small-cycle drilling fluid for 15-30 min, then opening the packer, and increasing the pressure of the vertical pipe until the bottom hole pressure meets the requirement of advanced injection working pressure, so as to ensure that the chemical wall-fixing agent invades the stratum;
(6) after the chemical solid wall slurry completely invades the stratum, releasing pressure, closing the packer, lifting the drill bit to a position 50-100 m above the bottom of the well, namely about 6300m, standing for 4-16 h and waiting for the chemical solid wall slurry to solidify;
(7) after the coagulation is finished, a drill bit is lowered to probe the plug, the drilling is continued, and the condition of well wall block falling and the condition of well diameter expansion rate are observed.
The product performance and the application effect of the examples are explained below.
(1) Core penetration ability
By adopting the chemical wall-fixing agent of the embodiment, the chemical wall-fixing agent can penetrate through a rock sample by injecting the chemical wall-fixing agent into loose sandstone at high pressure and maintaining the displacement pressure of 3-7 MPa for 5-20 min through visual observation. As can be seen from table 2, the shorter the time for the chemical wall-fixating agent to penetrate the rock sample as the slag particle size and the ultrafine calcite particle size decrease. Therefore, the chemical wall-fixing agent has better stratum natural fracture invasion capacity, and is a technical method capable of improving the borehole wall stability of fractured stratum in a large range.
TABLE 2 core penetration evaluation results
(2) Improving uniaxial compressive strength of rock
By adopting the chemical wall solidification agent of the embodiment, the chemical wall solidification agent is injected into the loose sandstone at high pressure, and after the working fluid completely invades the rock core, the rock core is taken out for uniaxial compressive strength test. As can be seen from fig. 5, the uniaxial compressive strength of the rock sample injected with the conventional chemical consolidating agent of comparative example 1 is improved by not more than 10%, and the uniaxial compressive strength of the rock sample injected with the chemical wall consolidating agent of the present invention is improved by not less than 50% compared with the loose sandstone in the original state. Therefore, the chemical wall-fixing agent has better rock strength improving capability, and is a technical method capable of improving the intensity of a fractured stratum in a large range and reducing the risk of borehole wall instability.
(3) Effectively maintain the stability of the well wall and reduce the hole diameter expansion rate
After the chemical wall-fixing agent for the fractured formation, the preparation method of the chemical wall-fixing agent and the advanced injection construction method are used, the stability of the well wall of the fractured zone stratum of 6500-6750 m of the TARIM-1 well is good, no obvious block falls in the drilling process, and the imaging logging result after drilling and uncovering shows that the well diameter expansion rate is only 10 percent and is obviously better than that of the fractured formation of an adjacent well.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications, changes or substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (12)
1. A chemical wall-solidifying agent for broken stratum is prepared from slags, bentonite, water glass, gypsum and superfine calcite.
2. A fractured formation chemical wall-fixing agent according to claim 1, wherein the chemical wall-fixing agent further comprises water, wherein the slag is 10 to 20 parts by weight, the bentonite is 3 to 10 parts by weight, the water glass is 3 to 10 parts by weight, the gypsum is 0.5 to 1.5 parts by weight, and the ultrafine calcite is 2 to 12 parts by weight, based on 100 parts by weight of the water.
3. The fractured formation chemical wall-fixing agent of claim 2, wherein:
based on 100 parts by weight of water, 15-20 parts by weight of slag, 3-5 parts by weight of bentonite, 3-6 parts by weight of water glass, 0.5-1 part by weight of gypsum and 2-10 parts by weight of ultrafine calcite.
4. A fractured formation chemical wall solidification agent according to any one of claims 1 to 3, wherein:
the particle size of the slag is less than 50 μm; and/or the presence of a gas in the gas,
the grain size of the superfine calcite is less than 30 mu m; and/or the presence of a gas in the gas,
the modulus of the water glass is 1.5-3.5, and the concentration of the water glass is 30-43 Be.
5. The fractured formation chemical wall-fixing agent of claim 4, wherein:
the particle size of the slag is 10-30 mu m; and/or the presence of a gas in the gas,
the particle size of the superfine calcite is 5-25 mu m; and/or the presence of a gas in the gas,
the modulus of the water glass is 1.5-3.0, and the concentration of the water glass is 35-43 Be.
6. A method for preparing a breakable chemical wall-fixing agent according to any one of claims 1 to 5, comprising mixing homogeneously the components comprising slag, bentonite, water glass, gypsum and ultrafine calcite.
7. The use of the chemical wall-fixing agent for fractured formation according to any one of claims 1 to 5 in drilling of oil and gas.
8. A construction method for advanced injection of chemical wall-fixing agent into fractured formation according to any one of claims 1 to 5, comprising injecting the chemical wall-fixing agent into fractured formation after the fractured zone is uncovered to a suitable depth until the chemical wall-fixing agent is solidified.
9. The construction method for the advanced injection of the chemical wall-fixing agent according to claim 8, characterized by comprising the following steps:
(1) adding a packer at the upper part close to the drill bit;
(2) carrying out deep fractured formation pre-drilling prediction;
(3) uncovering the proper depth of the broken zone, and injecting the chemical wall-fixing agent in advance;
(4) displacing the chemical wall-fixating agent into the formation;
(5) waiting for coagulation;
(6) the broken belt is torn off by drilling.
10. The construction method for the advanced injection of the chemical wall-fixing agent according to claim 9, characterized in that:
in the step (1), the drilling tool assembly is replaced: before the breakable stratum section is drilled, a packer is added near the upper part of the drill bit; and/or the presence of a gas in the gas,
in the step (2), predicting the deep fractured stratum before drilling: comprehensively utilizing logging rock debris and drilling parameter changes, predicting a crack development stratum in time, evaluating a stratum borehole wall instability risk, and performing advanced injection of a chemical wall-fixing agent when the borehole wall instability risk exists; and/or the presence of a gas in the gas,
in the step (3), the fractured stratum is properly uncovered, the chemical wall-fixing agent is injected into the shaft, and the drill bit is lifted to a position of 10-20 m of the chemical wall-fixing agent after the chemical wall-fixing agent is injected; and/or the presence of a gas in the gas,
in the step (4), the drill bit is kept stand, the small-cycle drilling fluid is used for 15-30 min, then the packer is opened, the pressure of the vertical pipe is increased until the bottom hole pressure meets the requirement of advanced injection working pressure, and the chemical wall-fixing agent is guaranteed to invade the stratum; and/or the presence of a gas in the gas,
in the step (5), after the chemical wall-fixing agent completely invades the stratum, the pressure is relieved, the packer is closed, the drill bit is lifted to 50-100 m above the bottom of the well, and the mixture is kept stand for 4-16 h for waiting for the chemical wall-fixing agent to be solidified; and/or the presence of a gas in the gas,
and (6) after the coagulation is finished, lowering a drill bit for plugging, and continuing drilling.
11. The construction method for the advanced injection of the chemical wall-fixing agent according to claim 9 or 10, characterized in that:
the packer is one of a multi-stage ball throwing packer, a multi-stage expansion packer and a multi-stage sliding sleeve packer.
12. The construction method for the advanced injection of the chemical wall-fixing agent according to claim 9 or 10, characterized in that:
prior to performing said step (1), developing a deep fractured formation geological prediction.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114961635A (en) * | 2022-06-10 | 2022-08-30 | 中国石油大学(北京) | Method and device for strengthening wall surrounding rock strength of well drilling well based on electromagnetic waves |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5309997A (en) * | 1992-10-22 | 1994-05-10 | Shell Oil Company | Well fluid for in-situ borehole repair |
| GB2373531A (en) * | 2001-03-20 | 2002-09-25 | Keller Ltd | Supporting foundations on contaminated land |
| CN102061151A (en) * | 2009-11-13 | 2011-05-18 | 中国石油化工股份有限公司 | Plugging bearing material for petroleum drilling, and preparation method and application thereof |
| CN104045271A (en) * | 2013-03-15 | 2014-09-17 | 中国石油化工股份有限公司 | Plugging agent for oil field or natural gas extraction and preparation method thereof |
| CN106398670A (en) * | 2015-07-28 | 2017-02-15 | 中国石油化工股份有限公司 | Three-proofing valve consolidation leak-stopping agent and applications thereof |
| CN110819321A (en) * | 2018-08-13 | 2020-02-21 | 中国石油化工股份有限公司 | Curing plugging agent, preparation method thereof and plugging slurry |
-
2020
- 2020-08-11 CN CN202010800873.6A patent/CN114075065B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5309997A (en) * | 1992-10-22 | 1994-05-10 | Shell Oil Company | Well fluid for in-situ borehole repair |
| GB2373531A (en) * | 2001-03-20 | 2002-09-25 | Keller Ltd | Supporting foundations on contaminated land |
| CN102061151A (en) * | 2009-11-13 | 2011-05-18 | 中国石油化工股份有限公司 | Plugging bearing material for petroleum drilling, and preparation method and application thereof |
| CN104045271A (en) * | 2013-03-15 | 2014-09-17 | 中国石油化工股份有限公司 | Plugging agent for oil field or natural gas extraction and preparation method thereof |
| CN106398670A (en) * | 2015-07-28 | 2017-02-15 | 中国石油化工股份有限公司 | Three-proofing valve consolidation leak-stopping agent and applications thereof |
| CN110819321A (en) * | 2018-08-13 | 2020-02-21 | 中国石油化工股份有限公司 | Curing plugging agent, preparation method thereof and plugging slurry |
Non-Patent Citations (2)
| Title |
|---|
| 王伟吉: ""顺北油气田破碎性地层井壁稳定技术难题与对策"", 《科学技术与工程》 * |
| 王李昌: "："复杂地层钻探堵漏浆液的研究与应用"", 《地质与勘探》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114961635A (en) * | 2022-06-10 | 2022-08-30 | 中国石油大学(北京) | Method and device for strengthening wall surrounding rock strength of well drilling well based on electromagnetic waves |
| CN114961635B (en) * | 2022-06-10 | 2023-11-10 | 中国石油大学(北京) | Method and device for strengthening surrounding rock strength of well wall of well drilling based on electromagnetic waves |
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