Method and device for predicting horizontal ground stress difference and storage medium

Abstract

The invention relates to a method and device for predicting the horizontal ground stress difference and a storage medium, and the method comprises the steps: determining values of input parameters of a horizontal crustal stress difference prediction model which is obtained by introducing horizontal stress disturbance caused by anisotropy into a combined spring crustal stress model, indicating the horizontal stress disturbance by the normal flexibility and Young modulus of the anisotropic medium, wherein the input parameters comprise vertical ground stress, fluid pressure, effective pressure coefficient, Poisson's ratio, Young modulus, normal flexibility, horizontal maximum principal strain and horizontal minimum principal strain; and determining the horizontal crustal stress difference according to the value of the input parameter by using a horizontal crustal stress difference prediction model. Compared with a horizontal crustal stress difference coefficient (DHSR), the method has the advantages that the practicability and the applicability are higher, and shale gas exploration and development can be effectively guided.

Description

technical field [0001] The present disclosure relates to the field of oil and gas exploration, in particular to a method, device and storage medium for predicting horizontal ground stress difference. Background technique [0002] In-situ stress is an important research content in the field of oil and gas exploration and development. Its important role runs through all stages. The exploration stage is closely related to the structure and its formation and evolution. The development stage is an important consideration for wellbore stability. At the same time, it can prevent casing damage during the production stage. Wait. The practice of shale gas exploration and development in recent years has revealed that the horizontal in-situ stress difference is a key parameter that determines whether fracturing can form a complex fracture network, and the evaluation and prediction of the horizontal in-situ stress difference is crucial for the commercial exploration and development of sh...

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Problems solved by technology

The data of the measurement method is more accurate, and the methods include acoustic emission method and hydraulic fracturing method, etc.; the logging method mainly uses the sound wave and density of the well logging, and calculates based on certain theories, and has certain applications in actual data, especially Professor Huang Rongzun (1983) considered the influence of tectonic stress on in-situ stress, selected different tectonic stress values ​​according to different regions, and established a calculation model of in-situ stress, called Huang's model. Later, some scholars based on the generalized Hooke's law The in-situ stress calculation model of homogeneous isotropic linear elastic medium is deduced, which is called the spring model; but these two methods can only be carried out on the basis of drilling, and the cost is high, especially they cannot be predicted and evaluated before drilling

[0004] In order to carry out effective pre-drilling prediction of underground media, numerical simulation is an effective method. By establishing a regional mechanical geological model and continuously adjusting boundary value iterative calculations to simulate the distribution of stress fields, this method has a low lateral resolution. And the calculation efficiency is low, which cannot meet the evaluation needs of large-area exploration three-dimensional areas

[0005] In the ground stress prediction method based on seismic data, the commonly used horizontal stress difference coefficient (DHSR) prediction method is the ground stress difference derived by Gray (2012) based on the basic theory of ground stress and seismic rock physics theory of seismic anisotropy medium. The quantitative relationship between coefficients and various elastic parameters and anisotropy parameters. This method is based on the assumption that the lateral displacement of the horizontal medium is zero. It can only realize the prediction of the horizontal stress difference ratio (DHSR), and cannot obtain the horizontal stress difference. The size of , affects the effective evaluation of in-situ stress

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