CN103590768A - Treatment method for abandoned uncased wells in coal mining area - Google Patents

Abstract

The invention provides a treatment method for abandoned uncased wells in a coal mining area. The treatment method comprises the four steps of well-mouth recovery, well unblocking and sweeping, well logging and three-section plugging. By means of the treatment of the abandoned oil and gas uncased wells in the coal mining area, as for each abandoned uncased well, about 100 thousands of tons of accumulated coal can be released, and direct economic loss of more than 50-million yuan can be reduced. In addition, by effectively treating the abandoned oil and gas uncased wells in the method, oil and gas leakage and various potential safety hazards are also avoided during mining, and various types of loss caused by movement are reduced.

Description

The discarded open hole well improvement method in coal mining region

Technical field

The present invention relates to the management domain of Oil/gas Well, particularly a kind of before mining in abandoned oil gas well area the improvement method of right discarded oil gas open hole well.

Background technology

The exploration and development of coal in China and petroleum gas is by two separate energy industry systems: coal system and petroleum gas system are independently born respectively.Because coal and petroleum gas are imbedded in underground objective occurrence condition difference and territorial characteristics separately, general coal seam is at underground shallow part, and oil-gas Layer is in underground deep below 1000 meters, in the some areas that occur coal seam and oil and gas field ply, mutually exploitation is each other had a great impact.Conventionally, in exploitation planning and designing separately, both sides take quarantine measures, colliery near establish in the certain limit in oil field isolated coal pillar, not exploit isolated coal pillar after coal deposits within the scope of oil field.Also keep at a distance with colliery in oil field as far as possible.In coal mining design scheme, according to pertinent regulations, reserving larger region security coal column can not exploit, and great waste all will, because oilfield exploitation or its leftover problem are postponed exploitation, even exploitation, have been caused for development of resources in the whole ore deposit, colliery even having.Wherein, in these abandoned oil gas wells, quite a few belongs to open hole well, and it forms reason is mainly owing to not getting to target zone in well-digging process, gave up halfway or dig a well to target zone but a little less than oil/gas show, without extraction value, drilling well troop is not lowered to production casing, directly discarded.The feature of open hole well is: 1, generally, oil-gas Layer pressure is little in this type of pit shaft, but affected by the periphery gas well water injection pressure that produces oil, and strata pressure may progressively raise; 2, owing to not being lowered to production casing, cave-in and drilling mud deposition make the middle and lower part of pit shaft closely knit by shutoff, and drifting difficulty is larger; 3, uncased wellbore intercepts without production casing, and as there being artesian aquifer in stratum, this pit shaft, as the direct UNICOM of conduit pipe coal mine down-hole tunnel, threatens greatly Safety of Coal Mine Production.Oil and gas leakage, the water in water layer of near this type of discarded oil gas open hole well colliery enter the problems such as colliery along oil well, it is one of immediate cause causing the accident potential such as overlapping Areas For Coal fire disaster, blast, toxic and harmful and water damage, for colliery normal design, production, brought great inconvenience and potential safety hazard, the exploitation in colliery simultaneously also can cause certain security threat to the Oil/gas Well of producing.The coal column of liberation flood tide is pressed coal, improves coal resources utilization rate, guarantees that the doulbe-sides' victory exploitation of coal and Oil Safety environmental protection and economy has become major issue anxious to be resolved in industry.

Summary of the invention

In order to address the above problem, the invention provides a kind of is the underground coal resource that safety economy is exploited and oil gas field is overlapping, the method for effectively administering discarded open hole well within the scope of field with "nine squares", colliery, to guarantee channel of coal mining working surface safety Oil/gas Well, and stop to occur oil gas leakage and cause environmental pollution accident.The present invention is directed to and do not carry out without production casing, isolating, discard the rear open hole well that spontaneous corrosion effect is obvious, situation is complicated in oil-gas mining, pit shaft, specifically improvement method comprises the steps:

(A) recover well head;

(B) through wash well: drifting and mud deposition section are disposed and well-flushing;

(C) well logging: obtain the casing programme data such as the formation informations such as oil-gas Layer position and pressure, water layer position and pressure, position, coal seam and Oil/gas Well well depth, hole deviation;

(D) syllogic shutoff: first paragraph, the oil-gas Layer shutoff of open hole well well barrel bottom section, packing oil gas; Second segment, the shutoff of pit shaft stage casing, and the examination of exerting pressure; The 3rd section; Surface pipe and well head shutoff.

Wherein, step (B) specifically comprises following two steps:

(1) drifting and the disposal of mud deposition section: use drifting vehicle in conventional pressure (4MPa left and right: 3.5-4.5MPa) lower boring ground drifting.Because open hole well is conventionally because cave-in and the residual meeting of drilling mud deposit thicker mud cake in pit shaft, drifting difficulty is large, easily there is bit freezing, crown drill accident, therefore need to be according to site operation judgement in drifting process, the thicker mud cake of deposition in running into pit shaft, drifting difficulty is large, while there is drilling rod reversion, back attack phenomenon, change as scraper bores mud cake is smashed, simultaneously, cementing truck pressure is increased to 5～6MPa, make the mud of smashing take ground out of by drifting circulation fluid;

(2) well-flushing: drifting, to desired depth, is lowered to cover washing cylinder and instrument oil pipe, with cementing truck, clear water is started by pit shaft bottom closed section, rinses back and forth piecemeal, until the flushing liquor that aperture is returned out does not dye hand.

Wherein, step (D) specifically comprises following four steps:

(1) oil-gas Layer shutoff: prepare 10% HTYT-1 high hydroscopic resin particle, squeeze this notes plugging material configuring to wellbore bottom;

(2) well wellbore stage casing shutoff:

1. injected water mud: be mixed with the cement paste of density >=1.82Kg/L with oil well cement, return and note to well head from shaft bottom by instrument oil pipe, Hou Ning 72 hours;

2. the examination of exerting pressure: use cementing truck pressure testing, checking plugging effect, 15Mpa exerts pressure, it is qualified that internal pressure decline in 30 minutes is no more than 0.5Mpa, if pressure drop surpasses 0.5Mpa, inject low-viscosity high-strength gel plugging material (as: amphion frozen glue profile control agent), Hou Ning is after 24 hours, again test pressure, until pressure is not only reduced to;

(3) surface pipe and well head shutoff: dial-out utility oil pipe, discharges well head, the full surface pipe of light water mud tank and the pit shaft of preparation density >=1.82Kg/L; (3) above well head, beat 0.5m * 0.5m * 0.5m clump, on clump face, indicate pound sign and shut-in well date, recover well site landforms.

Beneficial effect:

Through the above-mentioned improvement to coal mining region abandoned oil gas open hole well, every mouthful of abandoned well can solution bleed off pressure 100,000 tons of left and right of coal amount, reduces more than 5,000 ten thousand yuan of direct economic losses.In addition, the various potential safety hazards such as oil gas leakage in exploitation have also been avoided in effective improvement of abandoned oil gas well being carried out by method of the present invention, have reduced and have fallen every loss that face causes because of removal of home.

Current oil-gas mining mostly takes water filling to keep stratum energy production technique, the abandoned oil gas well in the same area, and when coal mining is passed through, the major safety risks that exist hydraulic oil, gas, water to leak.Contingent oil gas blast, toxic and harmful, water etc. are invaded the main security threats such as tunnel.By administering, can reduce to greatest extent these potential safety hazards.For safety in production provides reliable guarantee, the while is reclaiming coal resource to greatest extent.

Accompanying drawing explanation

Accompanying drawing 1 is the underground structure schematic diagram of the improvement method of the discarded open hole well of the present invention.

Wherein, A is topsoil; B is coal seam; C is artesian aquifer; D is oil-gas Layer;

The 1st, open hole well pit shaft; The 2nd, cement; The 3rd, high hydroscopic resin particle.

The specific embodiment

Below in conjunction with the specific embodiment, the present invention is described in more detail in the abandoned oil gas well improvement method in coal mining region.And protection scope of the present invention is not only confined to following embodiment.The those of ordinary skill of described technical field, according to above disclosure of the present invention, all can be realized object of the present invention.

It is specific as follows that XX ore deposit abandoned well open hole well is administered implementation step:

Preparation of construction

1. repair passway, be convenient to drifting working vehicle and pass through.

2. drifting troop prepares

1. drifting vehicle is one, and 700 type cementing trucks are a set of, more than instrument oil pipe 1200m;

2. Ф 73mm is tiltedly sharp 1;

3. high-pressure fire hose, elbow, joint are on deck, handy flexibly;

4. oil well cement is 15 tons, HTYT-1 high hydroscopic resin particle;

5. yb-250 well head is a set of;

6. instrument and fire-fighting equipment are pressed normal construction needs on deck;

7. Ф 100 screw drills are a set of, one of Ф 118 tricone bit, and Ф 118 scrapers bore one, Ф 190 cover washing cylinders;

8. 60m is excavated in well site ³one, blowdown hole.

Concrete steps:

(A) recover this abandoned well well head, and yb-250 well head is installed;

(B) through wash well

(1) drifting and mud deposition section are disposed: with drifting vehicle, adopt Ф 118 tricone bits and Ф 100 screw drills, bore mill drifting.Because open hole well is conventionally because cave-in and the residual meeting of drilling mud deposit thicker mud cake in pit shaft, drifting difficulty is large, easily there is bit freezing, crown drill accident, therefore in the time of need to there is drilling rod reversion, back attack phenomenon in drifting process, transposing is that the drill bits such as Ф 118 scrapers bore, the oblique point of Ф 73mm are smashed mud cake, meanwhile, 700 type cementing truck pressure are increased to 5～6MPa, make the mud of smashing take ground out of by drifting circulation fluid;

(2) well-flushing: drifting, to desired depth, is lowered to Ф 190 cover washing cylinder and instrument oil pipes, with 700 type cementing trucks, clear water is started by pit shaft bottom closed section, rinses back and forth piecemeal, until the flushing liquor that aperture is returned out does not dye hand.

(C) well logging

With engineering logging truck, carry out engineering log, the related datas such as admission reservoir depth, the coal seam degree of depth, water layer and casing programme.

(D) shutoff (syllogic shutoff)

(1) oil-gas Layer shutoff

HTYT-1 high hydroscopic resin particle with cementing truck hopper preparation 10%, injects to wellbore bottom the notes plugging material that this configures, and this resin material imbibition plays soft seal effect to oil gas interval, packing oil gas;

(2) well wellbore stage casing shutoff

1. injected water mud: with cementing truck, the oil well cement of having bought is mixed with to the cement paste of density >=1.82Kg/L, is returned and note to well head from shaft bottom by instrument oil pipe, Hou Ning 72 hours, realizes the shutoff to oil reservoir pit shaft stage casing.

2. the examination of exerting pressure: with 700 type cementing truck pressure testings, checking plugging effect, 15Mpa exerts pressure, it is qualified that internal pressure decline in 30 minutes is no more than 0.5Mpa, if pressure drop surpasses 0.5Mpa, inject amphion frozen glue profile control agent as plugging material, Hou Ning is after 24 hours, again test pressure, until pressure is not only reduced to;

(3) surface pipe and well head shutoff: dial-out utility oil pipe, discharges well head, the full surface pipe of light water mud tank and the pit shaft of preparation density >=1.82Kg/L; Above well head, beat 0.5m * 0.5m * 0.5m clump, on clump face, indicate pound sign and shut-in well date, recover well site landforms.

The scheme that above-mentioned embodiment is recorded not only can be applicable to abandoned oil open hole well, the gas open hole well in coal mining area, is applicable to too oil-gas mining unit to discarding open hole well environment protection treating etc.

Claims (5)

1. the useless open hole well improvement method in a coal mining region, is characterized in that the method comprises the steps:

(A) recover well head;

(B) through wash well: drifting and mud deposition section are disposed and well-flushing;

(C) well logging: obtain the casing programme data such as the formation informations such as oil-gas Layer position and pressure, water layer position and pressure, position, coal seam and Oil/gas Well well depth, hole deviation;

(D) syllogic shutoff: first paragraph, the oil-gas Layer shutoff of open hole well well barrel bottom section, packing oil gas; Second segment, the shutoff of pit shaft stage casing, and the examination of exerting pressure; The 3rd section; Surface pipe and well head shutoff.

2. the useless open hole well improvement method in coal mining according to claim 1 region, is characterized in that, step (B) specifically comprises following two steps:

(1) drifting and mud deposition section are disposed: under conventional pressure, bore mill drifting, the thicker mud cake of deposition in running into pit shaft, drifting difficulty is large, while there is drilling rod reversion, back attack phenomenon, transposing is smashed mud cake for drag bit, meanwhile, pressure increases to 5-6MPa, makes the mud of smashing take ground out of by drifting circulation fluid;

(2) well-flushing: drifting, to desired depth, is lowered to cover washing cylinder and instrument oil pipe, with cementing truck, clear water is started by pit shaft bottom closed section, rinses back and forth piecemeal, until the flushing liquor that aperture is returned out does not dye hand.

3. the useless open hole well improvement method in coal mining according to claim 2 region, is characterized in that described conventional pressure is 3.5-4.5MPa.

4. the useless open hole well improvement method in coal mining according to claim 1 region, is characterized in that, step (D) specifically comprises following four steps:

(1) oil-gas Layer shutoff: prepare 10% HTYT-1 high hydroscopic resin particle, inject to wellbore bottom the notes plugging material that this configures;

(2) well wellbore stage casing shutoff:

1. injected water mud: be mixed with the cement paste of density >=1.82Kg/L with oil well cement, return and note to well head from shaft bottom by instrument oil pipe, Hou Ning 72 hours;

2. the examination of exerting pressure: use cementing truck pressure testing, checking plugging effect, 15Mpa exerts pressure, it is qualified that internal pressure decline in 30 minutes is no more than 0.5Mpa, if pressure drop surpasses 0.5Mpa, injects amphion frozen glue profile control agent plugging material, after Hou Ning 24 hours, again test pressure, until pressure is not only reduced to;

(3) surface pipe and well head shutoff: dial-out utility oil pipe, discharges well head, the full surface pipe of light water mud tank and the pit shaft of preparation density >=1.82Kg/L; (3) above well head, beat 0.5m * 0.5m * 0.5m clump, on clump face, indicate pound sign and shut-in well date, recover well site landforms.

5. the useless open hole well improvement method in coal mining according to claim 4 region, is characterized in that described low-viscosity high-strength gel plugging material is amphion frozen glue profile control agent.

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