CN-121995454-A - Fractured tight oil reservoir saturation modeling method

Abstract

The invention discloses a fractured tight reservoir saturation modeling method which comprises the following steps of S100, constructing a fault model through well vibration combination, S200, using single well phases as hard data in the longitudinal direction under the constraint of a sedimentary phase mode, simulating sandstone phase distribution according to data analysis of a variation function as guidance on a plane, establishing a sandstone-mudstone spatial distribution model through an SIS random algorithm, S300, establishing a fractured three-dimensional geological model based on a seismic fusion attribute three-dimensional body and a sandstone three-dimensional model, S400, establishing a fault distance-saturation function through a fitting method, and establishing an oil-containing saturation three-dimensional geological model according to the function.

Inventors

• LI JUNLU
• WU JINWEI
• LIU XIAOHU
• REN HENG

Assignees

• 中国石油化工股份有限公司
• 中国石油化工股份有限公司华北油气分公司

Dates

Publication Date

20260508

Application Date

20241106

Claims (5)

1. 1. The method for modeling the saturation of the fractured tight oil reservoir is characterized by comprising the following steps of: S100, constructing a fault model by well earthquake combination; S200, under the constraint of a sedimentary facies mode, longitudinally utilizing single well facies as hard data, taking data analysis according to a variation function as guidance on a plane, simulating sandstone facies distribution by using an SIS random algorithm, and establishing a sandstone-mudstone spatial distribution model; s300, establishing a fracture phase three-dimensional geological model based on the seismic fusion attribute three-dimensional body and the sandstone three-dimensional model; S400, establishing a fault distance-saturation function by a fitting method, and establishing an oil saturation three-dimensional geological model according to the function.
2. 2. The method according to claim 1, wherein in the step S100, the fault model is constructed by: s110, based on three-dimensional seismic interpretation fault data, a fault model is established by utilizing petrel modeling software; s120, designing a model range, a grid direction and precision; s130, combining well vibration and establishing a three-dimensional structural layer model.
3. 3. The method according to claim 1, wherein in the step S200, the sandstone-mudstone spatial distribution model is established by: S210, establishing a sedimentary facies model by applying an assignment method on the basis of constructing a fault model; s220, coarsening the attribute of the sand-shale Shan Jingxiang; s230, under the constraint of a sedimentary facies model, taking single well coarsening as hard data, and establishing a sand-shale facies model by applying a sequential indication simulation algorithm according to the trend of data variation function analysis.
4. 4. The method for modeling the saturation level of a fractured tight reservoir according to claim 1, wherein in the step S300, a fracture phase three-dimensional model is established by: s310, analyzing fusion attributes of cracks; S320, establishing a sand shale phase model constraint fracture phase model.
5. 5. The method according to claim 1, wherein in the step S400, the oil saturation model is established by: s410, establishing a relation function between the fault distance and the oil saturation; s420, taking the fracture phase as a constraint, and establishing an oil saturation model according to the functional relation.

Description

Fractured tight oil reservoir saturation modeling method Technical Field The invention relates to the technical field of oilfield development, in particular to a method for modeling the saturation of a fractured tight oil reservoir. Background Compared with the conventional clastic rock reservoir, the compact sandstone reservoir with the crack development has the advantages that the heterogeneity is strong, the physical property distribution of the reservoir is complex, the oil content distribution is closely related to the development of fault cracks, the oil content saturation model of the fractured compact oil reservoir can be accurately established, and the method has important significance for the later numerical simulation and development scheme adjustment. Based on data such as seismic attributes, logging interpretation, geological stratification, reservoir dynamics and the like, on the basis of fine description of reservoirs and comprehensive evaluation of reservoirs, a fracture phase model under sediment phase constraint is established according to the transformation effect of fracture on the reservoirs and the control effect of oil and gas reservoir formation, further a porosity, permeability and saturation model is established according to the fracture phase, an oil-rich strip is characterized by combining production dynamic data, a fault distance and oil saturation relation function expression is established according to the existing data fitting fault and saturation relation of a single well region, and therefore a set of accurate compact sandstone reservoir three-dimensional geological modeling method based on sediment phase fracture phase control is established. In the prior art, the patent with the publication number of CN111274694A provides a saturation modeling method based on the constraint of an oil-containing boundary and an oil-water transition zone, and the method plays a certain role in establishing a saturation model constrained by the oil-containing boundary and the oil-water transition zone, but for a fractured tight oil reservoir, the definition of the boundary and the transition zone is extremely limited, the control effect of a fracture on the oil content cannot be described, and the method has extremely large errors in establishing the model for the fractured tight oil reservoir. The existing saturation modeling method has certain limitation, and the limitation is caused by the fact that firstly, a relation function of saturation and permeability is established according to an Archie formula so as to establish a saturation model, the attention point is a matrix pore of an oil reservoir, secondly, an oil-containing saturation model above the oil-water interface is established through an oil-water interface and a saturation altitude equation, the attention point is that a conventional permeability oil reservoir has poor effect on a compact oil reservoir. In conclusion, the modeling method based on the constraint of the oil-containing boundary and the oil-water transition zone is a conventional saturation modeling method, aims at conventional lithologic oil reservoirs and structural oil reservoirs, and cannot accurately control and describe the saturation field of cracks in the fractured compact oil reservoirs. Disclosure of Invention The invention aims to provide a method for modeling the saturation of a fractured tight oil reservoir, which is used for solving the problem that the conventional saturation modeling method cannot accurately describe the control of the saturation field by the fracture in the fractured tight oil reservoir in the oil reservoir exploration and development. The invention discloses a method for modeling the saturation of a fractured tight oil reservoir, which comprises the following steps: S100, constructing a fault model by well earthquake combination; S200, under the constraint of a sedimentary facies mode, longitudinally utilizing single well facies as hard data, taking data analysis according to a variation function as guidance on a plane, simulating sandstone facies distribution by using an SIS random algorithm, and establishing a sandstone-mudstone spatial distribution model; s300, establishing a fracture phase three-dimensional geological model based on the seismic fusion attribute three-dimensional body and the sandstone three-dimensional model; S400, establishing a fault distance-saturation function by a fitting method, and establishing an oil saturation three-dimensional geological model according to the function. Further, in the step S100, a fault model is constructed by the following method: s110, based on three-dimensional seismic interpretation fault data, a fault model is established by utilizing petrel modeling software; s120, designing a model range, a grid direction and precision; s130, combining well vibration and establishing a three-dimensional structural layer model. Further, in the step S200, a sand-mudstone spatially distributed m