Stratum pressure prediction method

Abstract

The invention relates to a stratum pressure prediction method comprising the following steps: building a first function relation between the stratum pressure and a pre-stack elasticity parameter; using an inversion method to obtain the pre-stack elasticity parameter value; obtaining the stratum pressure data according to the pre-stack elasticity parameter value solved by the inversion and the first function relation.

Description

technical field [0001] The invention belongs to the field of petroleum exploration and relates to a formation pressure prediction method. Background technique [0002] Formation pressure is a key parameter in drilling engineering design, which refers to the pressure acting on pore fluids (oil, gas, water) in rocks due to the compaction of sediments. At present, there are mainly two types of formation pressure evaluation methods commonly used: one is based on sediment compaction theory, mainly Eaton method, equivalent depth method and improved DC index method; the other is based on the effective stress theorem, through experiments or theoretical derivation, Establish the relationship model among P-wave velocity, effective stress and rock physical parameters. For example, the paper "The method and application of joint prediction of formation pressure by compressional wave velocity and shear wave velocity" (Natural Gas Geosciences, Vol. 26, No. 2) introduces a formation pressu...

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Problems solved by technology

Although the DC index obtained by the conventional tracking-while-drilling analysis can reflect the drillability of the formation, such an analysis can only provide information on the rock properties in a local area, and cannot reflect the change in the lateral distribution characteristics of the formation pressure;

[0004] (2) Predecessors mainly used the characteristic that P-wave velocity decreases with the increase of formation pressure to carry out pressure prediction, but the change of formation P-wave velocity is not only determined by the change of formation pressure. Strong, the accuracy of formation pressure prediction results is not high;

[0005] In addition, since the research of geophysical technology in the field of oil and gas exploration and development in recent years has mainly focused on the study of structures and reservoirs, there are few studies on the prediction of formation pressure, which is one of the important indicators for evaluating formations.

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