RU2285116C2 - Method for extracting deposits of bitumen and highly viscous oil and complex system of equipment for realization of said method - Google Patents

Abstract

FIELD: oil-extractive branch of industry, in particular, technology for extracting deposits of bitumen and highly viscous oil.

SUBSTANCE: during extraction of bitumen and highly viscous oil substances are diluted, liquefied and their viscosity is decreased by heating them by means of steam forced into beds. In accordance to invention, in the area being developed one or several wells are drilled with upper and lower side shafts, directed into depth of bed. They are encircled by rows of force wells. Steam is forced through wells, lower side shafts and force wells. Face-adjacent zone of bed is heated up together with product saturating it to temperature, at which its viscosity decreases and filtration into well is provided. The process is performed at speed, at which aside from depression, created in the bed by changes of face pressure, pressure of forced steam is used, forcing product towards the well, thus creating a rarefaction behind the forcing point of steam, causing additional depression along length of bed. Extraction of product is performed through wells and upper side shafts. Product is accumulated in the shaft of well above influx zone, which is separated from steam forcing zone by separating compactor. Product is extracted by deep-well pumps with usage of tubing pipes. For realization of method appropriate device is provided - complex system of surface-mounted and subterranean equipment.

EFFECT: increased efficiency of extraction.

2 cl, 6 dwg

Description

The invention relates to the oil industry, to the development of oil fields.

The aim of the invention is to increase oil recovery and reduce unit costs in the development of bitumen and high viscosity oil.

An analogue of the present invention can be a method for developing bitumen and high-viscosity oil by periodically supplying steam to heat the bottom-hole zone of individual wells, followed by the selection of heated oil with reduced viscosity along with condensed water / 1, 2 /.

The disadvantages of the analogue of the invention are:

- displacement of oil from the bottom-hole zones of wells and condensation of steam in the formation into water, causing the formation of cones of flooding and watering of wells.

The closest technical solution to increasing the efficiency of developing bitumen and high-viscosity oil is a mine production method with drifts built into the reservoir, to which they are filtered and flow through grooves or pipelines to collection points - in containers from which the products are pumped out. Maintenance of all underground and ground communications is carried out by oil workers, underground directly underground / 3 /.

The disadvantages of the method are:

- high material costs for the construction, arrangement and maintenance of devices;

- high fire hazard and hazardous working conditions.

The method of developing oil fields, which consists in the extraction of bitumen and highly viscous oils, their dissolution, liquefaction, viscosity reduction by heating with hot steam injected into the oil-bearing strata, is achieved by the fact that one or more mine wells are drilled in the developed area depending on the geological and technological conditions which are encircled by rows of injection wells for injecting hot steam into oil-bearing strata in order to heat their saturating products, in which the production of downhole products is is produced through mine wells, and steam injection is produced both through mine wells and injection wells, while through the mine wells additional heating of products located in the wellbore and products filtered into the well from the bottomhole formation zone, as well as for backwater it in the direction of the mine well, creating behind the steam supply point that is introduced into the reservoir through sidetracks drilled from the mine well, causing a certain vacuum, which also causes the appearance of additional depression and beyond its supply point, which extends to the depth of the oil reservoir while maintaining steady pressure at the bottom of the well, at which the pushing force, and therefore the influx of products towards the mine wells, is enhanced by backing up the heated oil with hot steam injected through injection wells, volume and injection pressure, which are established according to the adopted design grid for the development of a bitumen or oil reservoir, depending on the thickness of which, sidetracks designed for inflow flotation products into mine wells and for injecting steam, in which the zone of oil inflow from the injection zone in the shaft of the mine wells is separated by a separator, while the formation products coming from the upper zone are pumped out by deep pumps lowered on the tubing strings, and in hot steam is injected into the lower zone of the oil reservoir through the sidetracks, during which all maintenance operations carried out during the development of the oil field are carried out only from the surface of the earth (fi .1-6).

This goal is achieved by an integrated system of ground and underground equipment, in which for the production of bitumen and high-viscosity oils, large-diameter mine wells (1-1.5 m) and steam injection wells with d = 102 cm are drilled and the oil field is equiped, while mine wells along their axis lower the pipe string as a separator casing-centralizer, on which the centralizers are fixed on the grooves, consist of separate sheets and divide the wellbore along the cross section into separate vertices ical, if necessary, from two to four compartments, into which a steam injection pipe string is lowered inside the casing, and pipe lifting columns with deep pumps of various types and diameters are lowered into separate compartments, while the pipe string serving to inject steam descends to the bottom, to the bottom of the formation, where horizontal or inclined sidetracks are drilled from the well, the lower ones are equipped with pipelines for supplying steam, and the upper ones are for the influx of formation products into the well, they are separated from the lower ones by a separation line a denser, above which the product coming from the reservoir accumulates to a height at which the bottomhole pressure remains optimal and the established depression on the oil reservoir remains such that it decreases slightly to the inside of the reservoir to a certain depth due to horizontal shafts directed towards the mine well from steam injection wells, which constitute a single system of equipment and arrangement of an oil field for the implementation of the method of its development, in which steam steam injection tubing to a reservoir covered with a heat insulating material, and inside the reservoir are provided with steam return valves (Figures 1-6).

The method differs from the prototype in that bitumen and high-viscosity oils are extracted from oil deposits by heating the oil reservoir and saturating its products by injecting steam through both mine and steam injection wells located in rows around the mine well drilled to the bottom of the oil reservoir along the mine the grid vertically, and in the oil-bearing formation horizontally or inclined towards the shaft of the well based on the provision of uniformly varying heating as the filtration front changes astov production towards the mine well and ensuring a large coverage of the development zone by heating, and in formations having large thicknesses of their mine wells, sidetracks are drilled in tiers, while steam is pumped along the lower sidetracks, from the bottom up, and production is selected from the top formation, which is accumulated above with a separation seal installed to separate the steam injection zone from the extraction zone, in which the products entering the upper zone are pumped to the surface of the earth by deep pumps and ensuring conservation mode set operation of the well, i.e. a certain depression on the oil-bearing formation, adjusting its effect by changing the volumes and pressures of the steam injected both from the mine well and through the steam-injected wells.

The complex equipment system and their underground and ground devices differ from the prototype in mine wells, in them a protective-dividing casing-centralizer, in-depth pumping and ground equipment, where the steam supply zone is separated from the selection and recovery zone of the products coming from the formation, and by the wells located around mine wells, to which, like to mine wells, steam pipelines covered with heat-insulating material are connected, and in injection wells, the column on pine-compressor pipes to the oil reservoir, and bare in the oil reservoir, on which steam bypass valves are installed, in which all the underground equipment is serviced on the surface of the earth, which can significantly improve the safety of the entire system “mine wells - steam injection wells, deep-well underground and ground equipment. "

This allows us to conclude that the claimed invention is interconnected by a single inventive concept.

A comparison of these claimed technical solutions with the prototype made it possible to establish compliance with their criterion of "novelty."

In the study of other well-known technical solutions in these areas of engineering and technology, different inventive inventions from the prototype were not identified and therefore they provide the claimed technical solution with the criterion of "significant differences".

The method is carried out by ground and underground equipment that makes up a single oil field development system, which includes: mine wells 1, serving both for supplying a heat carrier — steam, and for producing well products, injection wells 2 — for injecting steam that are connected by a network on the earth’s surface steam pipelines 3 with steam generating units 4, oil pipelines 5, connecting mine wells 1 with a pre-treatment and sales unit 6, water pipelines 7 connecting them to a water pre-treatment unit I pump them through injection wells 8 into oil reservoirs, elevators 9 installed at the mouth of a mine well, wellhead equipment 10, a mine plate 11, electrical equipment 12, deep pumps 13, wellhead tees for venting gas 14 released in a mine well, pumping strings compressor pipes: for oil production 15, water 16, injection of steam 17, protective separation casing 18, production casing of a mine well 19, side shafts for injecting steam 20, side shafts for inflow of formation products 21, dividing densifier 22, steam bypass valves 23, safety valves 24, instrumentation 25.

The development method is carried out as follows: depending on the size of the explored areas of the oil deposits of the oil field, their structural forms, the thickness of the oil reservoirs, changes in the reservoir properties of the oil rocks, the areas from which the reservoir products can be drained into separate mine wells are determined. Next, it is determined how many mine wells, one or several, are required to be drilled to cover the entire oil-bearing area, which is also located taking into account the minimum costs for the construction of ground and underground utilities. Based on changes in the reservoir properties and the possible volume of incoming products in a separate mine well, a scheme for arranging the oil field’s area with underground and ground communications in the coverage area with a single mine well or the whole mine is determined.

When oil-bearing formations are composed of rocks with low reservoir properties, are saturated with high-viscosity oil and are unproductive, when the depression created from mine well 1 by lowering the bottomhole pressure in it is insufficient to ensure formation filtration at which oil production is cost-effective, to increase development coverage zones additionally create a pressure drop and heat the formation over large distances from the mine well, injecting small steam into it diameter 2 arranged in rows around a shaft hole (Figure 1). Moreover, depending on the temperature of the formation heating and the products saturating it, the viscosity of the product is reduced, which is also accompanied by an increase in its volume, the value of the reservoir pressure increases, which allows to increase the filtration rate of the product and, therefore, increase the coverage area by developing one mine well with the minimum the cost of funds to ensure the effective development of oil deposits of these categories. For this purpose, wells for injecting steam generated by steam generators 4, located on annular rows in a certain order, can have both inclined and horizontal shafts of a certain length, directed radially or semi-ring in shape, arranged in tiers depending on their thickness, providing for the formation to be heated both in thickness and in strike from mine wells.

In the case when the oil reservoir is confined to a small area and can be covered by development from one mine well (Fig. 2), it is usually placed on the arched part of the structure and drilled from it from the bottom — at the bottom of the formation — horizontal sidetracks in which pipelines for supplying steam, and horizontal and inclined sidetracks are drilled from the top of the reservoir and perforated pipelines are placed in them to ensure an optimal flow of products from the reservoir at a rational speed. formation from different depths of the formation, where it is composed of rocks with different reservoir properties, which is regulated both by maintaining a rational bottomhole pressure in the mine well and by heating the formation with its saturating products and creating various pressure drops by changing the quantity and pressure of the supplied steam, thereby regulating the magnitude of the depression and the creation of additional depression to the depth of the reservoir beyond the steam supply, as a result of an increase in the filtration rate in the direction of the mine well (figure 2).

When bitumen and viscous oils are produced from large oil fields composed of rocks having different reservoir properties, which are more efficient to be developed by separate mine wells with large coverage areas, both methods are used, with steam being supplied to oil reservoirs both through injection wells and steam and selection of reservoir products from a mine well.

When developing an oil field, an integrated system of ground and underground equipment works as follows: an oil field, depending on the size of the oil deposits, the shapes of the structures of the oil reservoir, their depth and thickness, the reservoir properties of the reservoir, is equipped with ground and underground equipment and is equipped according to a different scheme.

At the same time, when oil-bearing strata lie at shallow depths (up to 700 m), have different reservoir properties in oil-bearing area and in thickness, steam for heating the oil-producing stratum is pumped through wells, which are drilled around the shaft wells in rows along a specific grid to the oil-stratum vertically, and along the reservoir - horizontally, obliquely and in semicircles (figure 1). A pipe string with a heat-insulating coating is lowered into the wells to the oil reservoir, and bare pipes are pushed through the reservoir, where steam bypass valves for regulating pressure and flow rate 21 are installed. At the same time, lateral shafts are drilled radially from the wells in the inner rows to the mine well, which allows you to create the required temperature in the bottomhole formation zone and maintain a rational temperature inside the formation.

The inflow of reservoir products into the mine well, and then its pumping out of it is carried out by a deep pump 13, lowered into the mine well. If it is necessary to separate pump out the components of the stratified production of components, oil and water, in the well, they are separated by their densities, which are then pumped out by separate deep pumps installed at different depths. The product components raised to the surface are pushed to the points of their preparation and sale through separate pipelines, and the gas released in the mine well is transported as fuel to steam generators 4, hot steam from which is pumped into steam injection wells 2. Moreover, all surface equipment is placed on the basis of ensuring minimum the cost of heat loss during field development.

When the oil deposit is confined to oil deposits with a depth of more than 700 m, having low reservoir properties when producing bitumen or high viscosity oils, the development is carried out mainly using mine wells (Figs. 2, 5), from which, to certain depths, depending from their reservoir properties, horizontal and inclined sidetracks are drilled radially directed into the depth of the reservoir, as well as in reservoirs that have low reservoir properties with semicircles around a mine well, in reservoirs having x large thickness - in tiers. In this case, depending on the mechanical properties of the rocks, the lateral shafts can be left open without casing pipes, only with a guide tee installed at the side of the side of the hole entering the formation, which also serves as the sealant body, which is inserted at the entrance to the side shaft after the pipes are pushed into it, perforated in certain places, of different diameters, used to inject steam into the reservoir. In cases where the oil reservoir is composed of rocks that are prone to destruction, they are cased at the beginning of the production string and cementing is performed, followed by perforation of the face in certain places, into which the perforated pipes are then pushed to inject steam. After the completion of the arrangement of the lower part of the bottom of the mine well, a pipe string is lowered into it as a casing 18 with holes drilled along the entire length of the column, at the lower end of which a separator-seal is inserted, separating the perforated part of the face into two zones against the oil-bearing formation, a zone for steam injection into the zone of formation inflow, component-wise separation of it, accumulation of oil, water and gas in separate zones of the wellbore according to their densities and their separate pumping by deep pumps (ESP, GN) for different parameters their work with different depths, which is lowered into the various compartments, equipped tubing string serving as a casing 18 and steel plates, fixed on them belts. In this case, a string of pipes 17, which serves to inject steam, is lowered into the casing 18, and into the side compartments of the string of pipes 15, 16 with deep pumps 13 for separately pumping oil and water, the diameters of which are selected depending on the volumes of oil and water pumped to the surface of the earth.

In some cases, when it is technically possible, the water accumulated in the wellbore along one of the lateral shafts of the mine well can be pumped into concave portions of the relief of the oil reservoir occupied by water or beyond the oil content circuit.

In cases where the oil reservoir is composed of rocks having low reservoir properties, mine wells are built with certain small diameters, on a grid, with smaller distances from each other (Figs. 2, 5). At the same time, sidetracks for supplying steam in formations composed of rocks having strong mechanical properties can be produced through channels drilled into the oil-bearing formation for short distances, in which, if necessary, elongations over significant distances produce hydraulic jet perforation of the formation. In strata composed of rocks with insufficient strength, sidetracks are drilled at various, not great distances, cased with thick-walled strong pipes.

In those cases when oil-bearing strata are composed of rocks with medium reservoir properties and have medium or large developed areas, they are developed using both methods by injecting steam into the reservoir through separate injection wells and mine wells from which radial sidetracks are drilled to various removal from their faces (Fig.3.6). At the same time, their shafts drilled from opposite shafts in opposite directions at various distances can have straight, oblique, and semicircular shapes, into which pipes are pressed through at certain distances with plugged ends, and pipes are placed concentrically for them to inject steam with a bypass pressure regulating valve 21 at their ends, and outside the coverage area by heated steam injected from a mine well, wells are drilled around it only to inject steam into the formation, of which the main is torn between radial sidetracks drilled from a mine well. In addition to it, they are drilled at certain distances in the direction of other wells drilled in rows in the outer rows, that is, in the direction of the border between the development coverage zones between adjacent mine wells.

After drilling the coverage area with the development of a single mine well, they begin to equip and equip the mine well. After lowering the large-diameter mine production casing and pipes into it, a pipe string of the protective-separation casing 18 is lowered into the side shafts with side sheets fixed on them with belts that form separate compartments along the column cross section, a pipe string is lowered into the pipe casing 18 for injecting steam, and into the side compartments of the pipe string for pumping oil and water. The upper part of the mine well ends with a sealed wellhead pipe having a common metal plate 11 mounted on top of the production casing 19 depending on its diameter in various ways: threaded, bolted joints, which in the middle part are also supported fixed in the upper part to the production casing, and in the lower part installed in it by a separator-seal 22.

The pipe string used to inject steam 17, as well as other pipe columns used to suspend deep pumps and pump out individual components of the well products, are suspended on the column heads of wellhead fittings, which are installed in them using conical seals with an upper thrust nut, or a simple faceplate . The wellhead fittings 10 at the mouth of the mine well after the locking devices are connected, using bolt or threaded devices, to the corresponding pipelines: oil pipeline, water supply system, gas pipeline 14 directly to the collection and sale points established; when developing an oil deposit in one mine well, at a small distance from it, observing labor protection, nature and safety.

And in oil fields, where there are a significant number of mine wells and the development of oil deposits is carried out using both methods of steam injection, based on ensuring the minimum cost of funds and minimum heat loss, steam generators are located at the joints of the coverage zones of two, three mine wells, from which steam pipelines are laid to wells, and oil and water collection points are usually in the middle of the area, taking into account the points of their sale. Based on these conditions, the collection and sales pipelines are also located in the middle of the area where flow lines from individual mine wells are connected.

Information sources

1. Handbook of oil production. Volume II Edited by prof. I.M. Muraviev. State Scientific and Technical Publishing House of Oil and Mining and Fuel Literature. M. - 1959. - p. 96.

2. I.V. Lurie, B. A. Romanov. Equipment for oil production during thermal and steam treatment. M. - Nedra, 1979.

3. Handbook of oil production. Volume I. Under the general editorship of I.M. Muraviev. Gos. NTI of oil and mining and fuel literature. M. - 1958. - S. 508-533.

Claims (2)

1. A method of developing deposits of bitumen and high viscosity oil, which consists in the production of bitumen and high viscosity oil, in dissolving, liquefying and lowering their viscosity by heating with injected steam into the formations containing them, characterized in that one or more shaft wells with upper and the lower side shafts directed into the depth of the reservoir, which are surrounded by rows of injection wells, steam is injected through the mine wells, the lower side shafts and injection wells are heated the slaughter zone of the formation and its saturating products to a temperature at which they reduce its viscosity and provide filtration into the mine well at a speed at which, in addition to the depression created in the formation by changing the bottomhole pressure, injected steam pressure is used, pushing the product towards the mine well, creating the steam injection point is a rarefaction, which causes additional depression along the depth of the reservoir, while the production of products is carried out through mine wells and upper sidetracks, the products are accumulated They are buried in the shaft of a mine well above the inflow zone, which is separated from the steam injection zone by a separation seal, and this product is extracted by deep pumps using tubing. 2. A comprehensive system of ground and underground equipment for the extraction of bitumen and highly viscous oil, including production and injection wells, flow and receiving pipelines, columns of lifting and pressure tubing, deep pumps, characterized in that to improve the filtration from the bitumen formation and high viscosity oil used one or more shaft wells with upper and lower lateral shafts and injection wells, in the shaft wells lowered along their axis pipe string with holes as leather ears, and in them - columns of steam injection pipes with side sheets fixed to the casings, dividing the shafts of mine wells in cross section into separate vertical, if necessary, from two to four compartments into which the pipe columns are lowered for production, while the columns for injecting steam covered with heat-insulating material and lowered to the bottom to the bottom of the formation; for the injection of steam, the lower side shafts of the mine well are equipped, and its upper side shafts are equipped for production, in the shafts wells average interval separating reservoir installed seals separating the steam injection zone from the zone for the accumulation of products in its production.

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