A 3D rock mechanics parameter field modeling method for shale gas reservoirs

Abstract

The invention discloses a three-dimensional rock mechanics parameter field modeling method for a shale gas reservoir, comprising the following steps: collecting and arranging logging data and post-pressing evaluation result data of gas wells in a research area; Carry out triaxial rock mechanics test; establish the regression relationship between dynamic Young's modulus and static Young's modulus of the pilot hole, and establish the regression relationship between dynamic Poisson's ratio and static Poisson's ratio; Correct the data; calculate the static Young's modulus and static Poisson's ratio of the horizontal section; calculate the three-direction principal stress and correct it; according to the static Young's modulus and static Poisson's ratio of the pilot hole and horizontal section, and correct Based on the three-dimensional principal stress, the rock mechanics profile of the whole well section of the gas well is established; the layered data is interpreted according to the logging data, and the trend is constrained by the three-dimensional seismic data to establish a three-dimensional structural model; combined with the established rock mechanics profile of the whole well section and Three-dimensional structural model, establish rock mechanics parameter field model.

Description

technical field [0001] The invention relates to the technical field of petroleum and natural gas engineering, in particular to a modeling method for a three-dimensional rock mechanics parameter field of a shale gas reservoir. Background technique [0002] With the society's demand for clean energy, shale gas, as a new type of clean unconventional natural gas resource, has attracted more and more attention. Horizontal wells with long horizontal sections and staged hydraulic fracturing technologies are the key technologies to increase the production of single wells of shale gas in my country. With the exploration and development of shale gas going to deep layers, it is difficult to efficiently fracturing horizontal wells and the production of single wells is low and declining. The core of these difficult problems is still the development of shale reservoir fracture, failure and flow models, and its essence is still the rock mechanics of shale gas reservoirs. The petrophysical ...

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Problems solved by technology

[0005] (1) The length of the horizontal section of a shale gas horizontal well is generally about 1500-2000 m. Using the logging interpretation results of pilot wells to evaluate the rock mechanical properties around the well will have certain deviations, but the wellbore trajectory and logging Due to the limitation of instruments, there are usually only GR while drilling, resistivity and conventional acoustic logging in the horizontal section, and it is difficult to calculate dynamic rock mechanics parameters according to conventional methods;

[0006] (2) Although the main lithology of shale reservoirs is mudstone, due to the different content and distribution of mineral components such as calcium, silica and clay, the rock mechanics in the vertical and horizontal directions are quite different. The existing modeling process has not Consider the impact of this factor;

[0007] (3) Existing three-dimensional stress calculations are all based on theoretical formulas, and have not been corrected with the minimum horizontal principal stress of each fracturing stage obtained from post-fracture analysis, making it difficult to accurately evaluate the stress distribution around the well

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