CN-121997079-A - Method and device for optimizing five-stage sequence favorable region of sandstone gas reservoir

CN121997079ACN 121997079 ACN121997079 ACN 121997079ACN-121997079-A

Abstract

The invention relates to the technical field of oilfield development, in particular to a method and a device for optimizing a five-level sequence favorable region of a sandstone gas reservoir, wherein the method comprises the steps of carrying out four-level sequence division by utilizing a natural gamma well logging curve shape combined with a resistivity well logging curve on the basis of a three-level sequence division result; based on the four-level interval division result, natural gamma well logging curve, resistivity well logging curve and seismic data are utilized to carry out five-level interval division, division results of an effective reservoir distribution area and an effective through source fracture area are overlapped, an overlapping area of the effective reservoir distribution area and the effective through source fracture area is determined to be a source fracture favorable area, and a preferable result of the five-level interval favorable area of the conglomerate is determined according to the divided source fracture favorable area and the five-level interval division result. The invention defines the effective reservoir spreading characteristics, determines the source-break storage favorable region and realizes the system, accuracy and rapid optimization of the five-stage layer sequence favorable region of the sandstone gas reservoir.

Inventors

JI XUEYAN
LIANG SHUYI
LI WEI
GAO TAO
CAO BAOJUN
Wen Ruixia
ZHAO YONGQIANG
TONG MENG
WANG HAIYAN

Assignees

大庆油田有限责任公司
中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (19)

1. A method for optimizing a five-stage sequence of a conglomerate gas reservoir, comprising: Acquiring a three-level sequence dividing result, a natural gamma logging curve, a resistivity logging curve, seismic data, an effective through source fracture zone and an effective reservoir distribution zone dividing result of a reservoir in a research area; Based on the three-level sequence division result, performing four-level sequence division by utilizing the natural gamma logging curve form and the resistivity logging curve; Based on the four-level sequence division result, performing five-level sequence division by utilizing the natural gamma logging curve, the resistivity logging curve and the seismic data; Overlapping the division results of the effective reservoir distribution area and the effective through source fracture area, and determining the overlapping area of the effective reservoir distribution area and the effective through source fracture area as a source fracture advantageous area; And determining preferable results of the fifth-stage sequence favorable regions of the gritty according to the divided source-cut favorable regions and the fifth-stage sequence dividing results.
2. The method for optimizing five-stage sequence of a conglomerate gas reservoir according to claim 1, wherein effective through source fracture zone division is performed to obtain division results before the effective through source fracture zone division results are obtained, and the method comprises the following steps: Acquiring a reservoir source rock distribution diagram and a fault section diagram of a research area; On the source rock distribution diagram, dividing the range of a favorable region of the source rock according to the thickness of the source rock, the intensity of hydrocarbon generation, the total organic carbon content and the reflectivity of a mirror body; determining fault positions for communicating the source rock and the reservoir according to the fault section; And dividing an effective through source fracture zone within the range of the source rock favorable zone according to the fault position to obtain an effective through source fracture zone division result.
3. A method of optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 2, wherein the method of partitioning the range of the source rock zone according to the source rock thickness, hydrocarbon production intensity, total organic carbon content and specular reflectivity comprises: The range of the favorable region of the source rock is divided by taking the minimum lower limit of the thickness of the source rock larger than 535m, the strength of hydrocarbon generation larger than 200 hundred million square/km 2 , the total organic carbon content TOC larger than 2 percent and the specular reflectivity Ro larger than 2 percent.
4. The method for optimizing a five-level sequence of a sandstone gas reservoir according to claim 1, wherein the effective reservoir distribution area division is performed to obtain a division result before the effective reservoir distribution area division result is obtained, and the method comprises: obtaining a sediment phase zone depiction result of a research area; According to the logging curve, the lithology sensitive parameters of the sandstone are optimized; According to the lithology sensitive parameters, carrying out phase control sand prediction by taking a sediment phase zone depiction result as a constraint, and dividing a sand dominant sand distribution area; According to the logging curve, the sensitive parameters of the effective reservoir of the sandstone are optimized; and according to the effective reservoir sensitive parameters, on the basis of the dominant sand body distribution area of the sandstone, performing sand control effective reservoir prediction by taking the dominant sand body as a constraint, and dividing the effective reservoir distribution area.
5. The method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 4, wherein the investigation region deposition phase zone characterization is performed to obtain a characterization result before the investigation region deposition phase zone characterization result is obtained, and the method comprises: acquiring a single well deposition phase interpretation result of a research area, and drawing and generating a single well deposition phase diagram according to the single well deposition phase interpretation result; According to the single well sedimentary facies belt diagram, combining the sedimentary environment of the research area and the object source direction, carrying out seismic attribute optimization, and taking the optimized seismic attribute as a sedimentary facies belt sensitive attribute; And carrying out the etching of the deposition phase band according to the sensitive attribute of the deposition phase band to obtain an etching result of the deposition phase band.
6. A method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 5, wherein: the seismic attribute comprises a multi-attribute clustering attribute; The multi-attribute clustering attribute is that the coincidence rate of the sediment phase depiction result and the single well sediment phase interpretation result of each seismic attribute is determined, and the predetermined number of seismic attributes with the highest coincidence rate are clustered to obtain the multi-attribute clustering attribute.
7. A method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 5, wherein: the sensitive attribute of the deposition phase band is root mean square amplitude attribute.
8. A method for optimizing a five-level sequence of a sandstone gas reservoir according to claim 4, wherein the method for optimizing a lithology-sensitive parameter of a sandstone according to a logging curve comprises: Acquiring gamma, sound waves, density, resistivity and longitudinal wave impedance logging curves of a research area; correcting and standardizing the logging curve; and carrying out petrophysical analysis on the corrected and standardized logging curves, and taking the logging curve with the best distinction between the gritty and the mudstone as the lithology sensitive parameter.
9. A method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 8, wherein: The lithology sensitive parameter of the sandstone is a longitudinal wave impedance curve.
10. The method for optimizing a five-stage sequence favorable region of a sandstone gas reservoir according to claim 4, wherein the method for carrying out phase control sand prediction and dividing a sandstone dominant sand distribution region by taking a sediment phase zone characterization result as a constraint according to the lithology sensitivity parameter comprises the following steps: Interpolating the lithology sensitive parameters to generate lithology sensitive parameter bodies; and dividing the distribution area of the dominant sand body of the gritty according to the lithology sensitive parameter body and combining the gritty and mudstone dividing threshold value corresponding to the lithology sensitive parameter.
11. The method for optimizing a five-stage sequence favorable region of a sandstone gas reservoir according to claim 4, wherein the method for performing sand control effective reservoir prediction and dividing the effective reservoir distribution region on the basis of the sandstone dominant sand distribution region by taking dominant sand as a constraint according to the effective reservoir sensitivity parameters comprises the following steps: Interpolating the effective reservoir sensitive parameters to generate an effective reservoir sensitive parameter body; And dividing the effective reservoir distribution area according to the effective reservoir sensitive parameter body and combining the effective reservoir and the non-effective reservoir corresponding to the effective reservoir sensitive parameter.
12. The method for optimizing a five-stage sequence favorable region of a sandstone gas reservoir according to claim 1, wherein the method for performing four-stage sequence classification by utilizing the natural gamma well logging curve morphology in combination with a resistivity well logging curve on the basis of the three-stage sequence classification result comprises the following steps: if the natural gamma logging curve presents a low-value bell shape and a high-value gentle tooth shape, and the resistivity is changed from high to low, the junction of the two forms is a layering boundary; if the natural gamma logging curve presents a low-value peak shape and a high-value funnel shape, and the resistivity is changed from high to low, the junction of the two forms is a layering boundary; if the natural gamma logging curve presents a high-value gentle line shape and a low-value funnel shape, and the resistivity is changed from low to high, the junction of the two forms is a layering boundary; if the natural gamma log exhibits a high value line shape and a high value box shape, and the resistivity is changed from low to high, the junction of the two morphologies is a layering boundary.
13. The method for optimizing a five-level sequence favorable region of a sandstone gas reservoir according to claim 1, wherein the method for performing five-level sequence classification by using the natural gamma log and resistivity log and seismic data based on the four-level sequence classification result comprises the following steps: Carrying out single-well five-stage layer sequence boundary division in a four-stage layer sequence grid by utilizing the natural gamma and resistivity curves and combining the gyratory characteristics; Determining amplitude characteristics in the corresponding seismic data according to the single-well five-level layer sequence boundary dividing result; And according to the amplitude characteristics, carrying out inter-well five-stage sequence boundary division in the four-stage sequence lattice frame to obtain a five-stage sequence division result.
14. The method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 13, wherein the method for performing single-well five-stage sequence demarcation within a four-stage sequence grid by utilizing the natural gamma and resistivity curves and combining a rotation characteristic comprises the following steps: In the four-level layer sequence lattice frame, the natural gamma curve and the resistivity curve are utilized to identify a water inlet interface, a water outlet interface and a lake flooding surface of the four-level gyratory; In the sandstone development interval, the sandstone interface closest to the lake flooding surface in the gyratory contact interface is used as a single-well five-level interval boundary, and in the sandstone development interval, according to comprehensive well logging interpretation results, the interfaces of the gas layer, the gas difference boundary layer and the dry layer closest to the water inlet interface and the water outlet interface in the gyratory contact interface are used as single-well five-level interval boundaries.
15. The method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 14, wherein the method for identifying a water inlet interface, a water outlet interface and a lake flooding surface of a four-stage rotation by utilizing the natural gamma curve and the resistivity curve in a four-stage sequence grid comprises the following steps: determining the gyratory characteristic of the mudstone development area as forward gyratory or reverse gyratory according to the gamma and resistivity curves; In the region of the worst development of the mudstone, the contact interface between the two forward gyrations is a water inlet interface, and the contact interface between the two reverse gyrations is a water outlet interface; in the region with the best development of the mudstone, the contact interface between two forward gyrations and the contact interface between two reverse gyrations are lake flooding surfaces; In the region of the mudstone development middle, the contact interface between the forward rotation and the reverse rotation is the lake flooding surface.
16. A method for optimizing a five-stage sequence of a conglomerate gas reservoir according to claim 1, wherein: when the five-level layer sequence division is carried out, the thickness of the divided layer sequence is less than 100m.
17. The method for optimizing a five-stage sequence of a sandstone gas reservoir according to claim 1, further comprising: Acquiring economic and technical limits of a dessert of a conglomerate gas reservoir in a research area, wherein the economic and technical limits at least comprise single well yield, reservoir thickness and horizontal segment length; and determining the sandstone gas reservoir dessert area in the favorable region of the five-stage sequence of the sandstone according to the economic and technical limit.
18. A method of optimizing a five-level sequence benefit of a conglomerate gas reservoir according to claim 17, wherein said economic and technical limits are determined prior to said acquiring of a conglomerate gas reservoir dessert economic and technical limit in an investigation region, the method comprising: And (3) establishing an economic evaluation model, and comprehensively determining the single well yield, the reservoir thickness and the horizontal section length by applying a full life cycle evaluation method and combining the drilling and completion investment, the operation cost, the natural gas commodity price and the life cycle of the sandstone gas reservoir.
19. A device for optimizing a five-stage sequence of a conglomerate gas reservoir, comprising: The acquisition unit is used for acquiring three-level layer sequence division results of the reservoir in the research area, a natural gamma logging curve, a resistivity logging curve, seismic data, an effective through source fracture area and effective reservoir distribution area division results; The four-level sequence dividing unit is used for carrying out four-level sequence division by utilizing the natural gamma well logging curve form and the resistivity well logging curve on the basis of the three-level sequence dividing result; The five-level sequence dividing unit is used for carrying out five-level sequence division by utilizing the natural gamma logging curve, the resistivity logging curve and the seismic data on the basis of the four-level sequence dividing result; The source-disconnected storage favorable region determining unit is used for overlapping the division results of the effective reservoir distribution region and the effective through source fracture region, and determining the overlapping region of the effective reservoir distribution region and the effective through source fracture region as the source-disconnected storage favorable region; And the fifth-level sequence favorable region determining unit is used for determining a preferable result of the fifth-level sequence favorable region of the conglomerate according to the divided source storage favorable region and the fifth-level sequence dividing result.

Description

Method and device for optimizing five-stage sequence favorable region of sandstone gas reservoir Technical Field The invention relates to the technical field of oilfield development, in particular to a method and a device for optimizing a five-stage sequence favorable region of a sandstone gas reservoir. Background Under the condition that exploration and exploration of reserve areas are more and more difficult, the yield of the development stage is improved, and the method plays an important role in continuous and stable production of gas fields. However, the optimization of the favorable region in the development stage is more demanding than the requirement in the exploration stage, the evaluation of the favorable region of the prior sand reservoir is mainly concentrated in the exploration stage through investigation, the research of the source-break storage relationship is not deep, the range of the source-break storage favorable region is not clear, the research of the sedimentary facies, the storage layer and the favorable region also stays on the three-stage layer sequence, the longitudinal thickness of the three-stage layer sequence is large and is 324m on average, the range of the planar favorable region is large, and the prediction precision is not high. Aiming at the problem that the preferable layer sequence division of the favorable region of the sandstone gas reservoir is not fine, a set of preferable method suitable for the favorable region of the development stage of the sandstone gas reservoir needs to be established, and the accurate deployment of well positions is guided. Disclosure of Invention The invention provides a method and a device for optimizing five-stage layer sequence favorable regions of a sandstone gas reservoir, which are used for solving the problems that when the favorable regions are optimized in the prior art, the range of the source-broken favorable regions is not clear, only three-stage layer sequence division is carried out, the longitudinal thickness of a division result is large, the division is not fine enough, the range of the plane favorable regions is large, and the prediction precision is low. According to an aspect of the present invention, there is provided a method of optimizing a five-stage sequence of a conglomerate gas reservoir, comprising: Acquiring a three-level sequence dividing result, a natural gamma logging curve, a resistivity logging curve, seismic data, an effective through source fracture zone and an effective reservoir distribution zone dividing result of a reservoir in a research area; Based on the three-level sequence division result, performing four-level sequence division by utilizing the natural gamma logging curve form and the resistivity logging curve; Based on the four-level sequence division result, performing five-level sequence division by utilizing the natural gamma logging curve, the resistivity logging curve and the seismic data; Overlapping the division results of the effective reservoir distribution area and the effective through source fracture area, and determining the overlapping area of the effective reservoir distribution area and the effective through source fracture area as a source fracture advantageous area; And determining preferable results of the fifth-stage sequence favorable regions of the gritty according to the divided source-cut favorable regions and the fifth-stage sequence dividing results. Preferably, before the effective through source fracture zone division result is obtained, effective through source fracture zone division is performed to obtain a division result, and the method comprises the following steps: Acquiring a reservoir source rock distribution diagram and a fault section diagram of a research area; On the source rock distribution diagram, dividing the range of a favorable region of the source rock according to the thickness of the source rock, the intensity of hydrocarbon generation, the total organic carbon content and the reflectivity of a mirror body; determining fault positions for communicating the source rock and the reservoir according to the fault section; And dividing an effective through source fracture zone within the range of the source rock favorable zone according to the fault position to obtain an effective through source fracture zone division result. Preferably, the method for dividing the range of the beneficial area of the source rock according to the thickness of the source rock, the strength of hydrocarbon generation, the total organic carbon content and the reflectivity of the vitrinite comprises the following steps: The range of the favorable region of the source rock is divided by taking the minimum lower limit of the thickness of the source rock larger than 535m, the strength of hydrocarbon generation larger than 200 hundred million square/km 2, the total organic carbon content TOC larger than 2 percent and the specular reflectivity Ro larger than 2 percent. Preferably