A Prediction Method for Overpressure in Undercompacted and Hydrocarbon-Gene Mixed Genesis Formation

Abstract

The invention discloses a method for predicting the overpressure of under-compacted and hydrocarbon-generated formations, with the purpose of providing a development area where under-compacted and hydrocarbon-generated two genetic mechanisms exist simultaneously, which jointly lead to formation pore overpressure A method for quantitative formation pressure prediction. The new method adopts the idea of ​​quantifying and characterizing the contributions of undercompaction and hydrocarbon generation overpressure respectively and finally superimposing them. On the basis of calculating the overpressure contribution of undercompaction factors based on the velocity reduction, the TOC content of formations is creatively superimposed. Pre-earthquake prediction is connected with hydrocarbon generation pressurization, which provides a new method for prediction of mixed-origin overpressure that is simpler and more intuitive than the existing method based on loading / unloading theory such as Bowers. This method avoids the risk of reducing the prediction accuracy caused by adjusting the undercompaction or hydrocarbon generation prediction model parameters to approximate the result of mixed origin, and also avoids the complex regional parameter determination steps of the bowers loading / unloading curve overpressure prediction method, and the calculation results are more accurate. for stability.

Description

Technical field: [0001] The invention belongs to the field of oil and gas field exploration, in particular to a method for predicting the overpressure of under-compacted and hydrocarbon-generated formations. Background technique: [0002] Abnormally high formation pressures generally exist in geologically relatively late sedimentary environments, and their development patterns are very complex in most areas. Predicting the distribution of pore pressure in underground rock formations (hereinafter referred to as formation pressure) before drilling for oil and gas exploration plays a vital role in rationally configuring the mud system to ensure drilling safety. [0003] The causes of abnormal overpressure in the formation mainly include the underpressure caused by the rapid deposition of clay minerals, the pressurization of hydrocarbon generation caused by the discharge of liquid or gaseous hydrocarbons associated with organic diagenesis, and the pressure rise caused by tectoni...

AI Technical Summary

Problems solved by technology

[0014] In order to solve the problems existing in the prior art, the present invention provides a method for predicting the overpressure of under-compacted and hydrocarbon-generated formations, which solves the problem in the prior art when the dominant factor is unknown or multiple factors cannot be ignored. Prone to problems such as parameter optimization and further improvement of speed accuracy requirements

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