RU2657584C1 - Method of developing an oil field with a fractured reservoir - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to petroleum industry and can find application in development of an oil reservoir with a fractured reservoir. By the method a pilot well is drilled. According to the data of geophysical studies in the productive reservoir of the prevailing direction of fracture of the field. From the pilot bore hole the same multidirectional paired horizontal trunks, which are directed to opposite sides from the well, are drilled. First pair of horizontal trunks are drilled perpendicular to the direction of natural fracturing. In this case after posting of each horizontal barrel by selection, the increase in production rate in the pilot vertical well is determined. After completion of construction of horizontal trunks, the increment of the rates of paired trunks is summarized. Select the two most productive pairs of trunks. When viewed from above in the direction of the pairs, vectors are created starting in the pilot vertical borehole, proportional to the total production rate of these pairs with an angle between them not exceeding 90°. Summarize the resulting vectors. In parallel to the direction of the resulting vector, the entire reservoir is equipped with horizontal production wells and injection wells. Pumping of working agent is done through injection wells and recovery of products through multi-hole production wells.

EFFECT: increase efficiency of development by taking into account direction of the actual migration of products in the formation, as well as simplifying development and its cheaper.

1 cl, 1 ex, 1 dwg

Description

The invention relates to the oil industry and may find application in the development of an oil reservoir with a fractured reservoir.

A known method of developing oil deposits in carbonate reservoirs (patent RU No. 2424425, IPC ЕВВ 43/20, publ. Bull. No. 20 dated 07/20/2011), including drilling production and injection wells, pumping a working agent through injection wells and selecting products through production wells , studies to determine the prevailing direction of fracture of the reservoir, zones with minimum and average fracture density, and in areas with minimum and average fracture density with oil-saturated layer thicknesses of at least 10 m additional horizontal and / or branched horizontal wells are drilled, and horizontal wells are placed in the formation at an angle of 50-70 ° to the prevailing direction of fracturing of the reservoir, and wells located in the corresponding zones of fracture density at a minimum distance from horizontal and / or branched wells are also used as injection wells horizontal wellbores.

There is also a method of developing fractured reservoirs (patent RU No. 2526037, IPC ЕВВ 43/20, publ. Bull. No. 23 of 08/20/2014), including the determination of fracturing or decompression lines of a deposit, the construction of production and injection wells taking into account the fracture of the reservoir, injection of displacing agent into injection wells and oil extraction through production wells, moreover, a section of a deposit with oil-saturated thicknesses of more than 10 m is selected to prevent rapid flooding of produced oil with bottom water, the location of nodes is determined once of marshes - intersections of decompression lines, production wells are drilled along an uneven grid in the form of vertical wells with penetration into decompression units or in the form of lateral or lateral horizontal shafts with intersection of nearby decompression lines communicated with decompression units, injection horizontal wells are located in compacted carbonate reservoirs, between several decompression nodes perpendicular to the prevailing direction of reservoir fracture.

The disadvantage of these methods is the difficulty in the implementation and construction of industrial wells, since it is difficult to ensure that they get exactly into the decompression units, in addition, the construction of production wells is based on the estimated estimation of the distribution of the formation products without taking into account the determination of its actual migration in the formation.

A method of developing an oil reservoir with a pore-cavernous-fractured reservoir (patent RU No. 2474679, IPC ЕВВ 43/20, publ. Bull. No. 04 of 02/10/2013), including opening the reservoir by drilling the pilot shaft, placing means for cutting in the pilot barrel with the ability to set the zenith angle to enter a horizontal section during drilling, launch a production string, conduct geophysical surveys and drill horizontal shafts from a horizontal horizontal pilot shaft in a reservoir, and before drilling, according to Geophysical surveys determine the dominant direction of natural fractures in the reservoir, estimate the width of the increased fracture zone, place horizontal boreholes mainly perpendicular to the direction of natural fracture, with faces removed at a distance of at least 40 m, for each horizontal bore, determine the drilling corridor in which the drilling ceiling is limited by the roof of the reservoir, and the bottom of the drilling corridor is assigned at a distance from the roof not more than 1/2 of the thickness of the reservoir, but not less than 2 m to the oil-water contact, the entry point into the reservoir is prescribed by determining the technical feasibility of establishing the curvature of the trunk, the length of the pilot shaft from the entry point to the proposed zone of increased fracturing is chosen to enable drilling of the second and the third barrel with an entrance to the zone of increased fracture with an zenith angle in the range of 80-95 ° and with a departure from the pilot shaft of at least 40 m, according to the results of piloting in the zone the width of this zone, the length of the pilot shaft is limited by the passage of the zone of increased fracture, on the basis of geological reference to the pilot shaft, the second shaft is drilled at a distance that allows the opening of the zone of increased fracture in the roof of the drilling corridor, with entry into the zone of increased fracture with anti-aircraft an angle in the range of 80-95 °, with a departure from the pilot shaft of at least 40 m, passing through the zone of increased fracture in the roofing part of the corridor rhenium and a departure from the pilot shaft of at least 40 m, the third barrel is drilled from the opposite side of the pilot barrel relative to the second barrel at a distance that makes it possible to open the zone of increased fracture in the bottom of the drilling corridor, entering the zone of increased fracture with an zenith angle in the range of 80 -95 °, with a departure from the pilot shaft of at least 40 m, passage of an increased fracture zone in the bottom of the drilling corridor, and a departure of at least 40 m from the pilot shaft, through a hole nnuyu well taken Plast products.

The disadvantages of this method are the complexity and high cost of implementation, since it is necessary to comply with a large number of requirements for well construction, while it is practically impossible to implement such a method in deposits located on areas of more than 10 km ² , since for each well it is necessary to conduct research individually, also construction wells is carried out on the basis of the estimated assessment of the distribution of reservoir products without taking into account the determination of its actual migration in the reservoir.

The technical objectives of the invention are to simplify and reduce the cost of the method of developing an oil reservoir with a fractured reservoir, implemented taking into account the direction of the actual migration of products in the reservoir.

Technical problems are solved by the method of developing an oil reservoir with a fractured reservoir, including drilling a pilot well, determining, according to geophysical studies in a productive reservoir, the prevailing direction of fracturing of the reservoir, drilling from the pilot well horizontal wells in the reservoir, at least one of which is drilled perpendicular to the direction of natural fracturing, construction of production and injection wells, injection of a working agent through injection wells and about Forest products through production wells.

What is new is that identical multidirectional paired horizontal trunks are drawn from a pilot vertical well, with paired trunks directed in opposite directions and only the first pair of horizontal trunks are drilled perpendicular to the direction of natural fracturing, after each horizontal well is sampled, the increase in production rate in the pilot vertical well is determined. upon completion of the construction of horizontal shafts, the increase in the production rates of paired shafts is summarized, two of the most selected e productive pairs of trunks, and when viewed from above in the direction of these pairs, vectors are constructed with the beginning in the pilot vertical well proportional to the total production rate of these pairs with an angle between them not exceeding 90 °, the vectors obtained are summed, and the entire reservoir is equipped with the horizontal production wells parallel to the direction of the obtained vector and injection wells.

The drawing shows from above a pilot well with paired multidirectional horizontal boreholes with vectors proportional to the total production of paired wells.

A method of developing an oil reservoir 1 with a fractured reservoir includes drilling a pilot well 2, determining, according to geophysical studies in a reservoir, the prevailing direction of fracturing of reservoir 1, drilling from a pilot well 2 of identical multidirectional paired horizontal shafts 3 and 3 ', 4 and 4', 5 and 5 '(see patents RU No. 2252563, 2265711, 2333340, etc.), which are directed in opposite directions from well 2. Moreover, the first pair of horizontal shafts 3 and 3' is drilled perpendicular to the direction of natural fracturing . Drilling of oppositely directed shafts 3 and 3 ', 4 and 4', 5 and 5 'excludes errors associated with the accidental hit of one of these shafts 3, 3', 4, 4 ', 5 or 5' in the area of reservoir 1 with different the rest of the reservoir 1 by parameters (for example, an oil-bearing lens, the interlayer is a non-collector, etc.), with a spread of flow rates of more than 25% in one of the pairs of trunks 3 and 3 ', 4 and 4', 5 and 5 'higher or lower a new well is drilled (not shown in FIGS. 1 and 2) from well 2 parallel to one of the trunks 3, 3 ', 4, 4', 5 or 5 'in this pair, while the production rate of this well is summed with the production rate trunk 3, 3 ', 4, 4', 5 or 5 ', with which the spread does not exceed 25%, with a spread of flow rates in several pairs of oppositely directed trunks 3 and 3', 4 and 4 ', 5 and 5' more than 25% drill a new well 2 (this rarely happens, as practice has shown, in no more than 2%). After each horizontal well 3, 3 ', 4, 4', 5, and 5 'is selected, the increase in production rate in the pilot vertical well 2 is determined by selection. Upon completion of the construction of horizontal horizontal wells 3, 3', 4, 4 ', 5, and 5', the flow rates paired trunks 3 s 3 ', 4 s 4' and 5 s 5 'are summarized. The two most productive pairs of trunks 3, 3 'and 4, 4' are selected in total terms; when viewed from above in the direction of pairs 3, 3 'and 4, 4', vectors 6 and 7 are constructed with the beginning in the pilot vertical well 2, proportional to the total production of these pairs 3, 3 'and 4, 4' with an angle α between them not exceeding 90 ° (α≤90 °). The obtained vectors 6 and 7 are summarized, vector 8 is obtained. Parallel to the direction of the obtained vector 8 (± 10% due to errors in well construction), the entire reservoir is equipped with horizontal producing wells 9 and injection wells 10. The working agent is pumped through injection wells 10 and products are selected through producing wells 9.

An example of a specific implementation.

A pilot well 2 was drilled on fractured reservoir 1. According to geophysical studies, the prevailing fracture direction of reservoir 1 was determined in a productive reservoir. A pair of trunks 3 and 3 'were drilled from well 2 perpendicular to the prevailing fracture, and the total production rate of these trunks 3 and 3' was determined by selection 13.7 t / day Then we drilled trunk 4 and, while other trunks 3 and 3 'were blocked by equipment, we determined the flow rate of this trunk 4, which amounted to 5.4 tons / day, by selection. In a similar way, the flow rates of the remaining trunks were sequentially determined: 4 '(6.0 t / day), 5 (2.3 t / day) and 5' (2.0 t / day). The production rates of pairs of trunks totaled 4 s 4 '(11.4 t / day) and 5 s 5' (4.3 t / day). The most productive pairs were 3 and 3 '- 13.7 t / day, 4 and 4' - 11.4 t / day. When viewed from above in the direction of pairs 3, 3 'and 4, 4', vectors 6 and 7 were constructed with the beginning in the pilot vertical well 2, proportional to the total flow rate of these pairs 3, 3 'and 4, 4', respectively, with an angle between them α≈60 °. The obtained vectors 6 and 7 were summarized, a vector 8 was obtained, parallel to the direction (± 10% due to errors in well construction) of which horizontal production wells 9, injection vertical 10 and injection horizontal 10 'wells are constructed using any known grid. The working agent (water) was pumped through 10.10 'injection wells and the products of reservoir 1 were taken through horizontal production wells 9. Compared to the analogue developed at the same reservoir 1, the increase in production was 24%.

The proposed method for the development of an oil reservoir with a fractured reservoir is simple, cheap and effective, as it is implemented taking into account the direction of the actual migration of products in the reservoir.

Claims (1)

A method for developing an oil reservoir with a fractured reservoir, including drilling a pilot well, determining, according to geophysical studies in a productive reservoir, the prevailing direction of fracturing, drilling from a pilot well a horizontal wellbore in a reservoir, at least one of which is drilled perpendicular to the direction of natural fracturing, producing and injection wells, injection of a working agent through injection wells and selection of products through production characterized by the fact that identical multidirectional paired horizontal trunks are drawn from the pilot vertical well, and the paired trunks are directed in opposite directions and only the first pair of horizontal trunks are drilled perpendicular to the direction of natural fracturing, after each horizontal wellbore is selected, the increase in production rate in the pilot vertical well, upon completion of the construction of horizontal shafts, the increase in the production rates of paired shafts is summarized, selected for The most productive pairs of trunks, when viewed from above in the direction of these pairs, construct vectors with a beginning in a pilot vertical well, proportional to the total production of these pairs, with an angle between them not exceeding 90 °, summarize the vectors obtained, parallel to the direction of the resulting vector equip the entire reservoir with horizontal producing wells and injection wells.

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