Supercharging effect force-considering hole-wall collapsing pressure calculation method

Abstract

The invention discloses a supercharging effect force-considering hole-wall collapsing pressure calculation method, and belongs to the field of oil drilling. The method comprises the following steps of: obtaining a stratum parameter and a drilling fluid density from geological information, logging information and drilling information of a selected area; obtaining a mud cake penetration rate from drilling fluid penetration experiment information of the selected area; obtaining a rock mechanical parameter from rock mechanical experiment information and the logging information of the selected area; obtaining a supercharging effect force coefficient according to the stratum parameter, the drilling fluid density and the mud cake penetration rate; and substituting the rock mechanical parameter, the stratum parameter and the supercharging effect force coefficient into a hole-wall collapsing pressure model to obtain hole-wall collapsing pressure. According to the method, the hole-wall stress features under drilling fluid environment can be reflected more really, and basis is provided or the selection of reasonable drilling fluid density in the drilling process.

Description

technical field [0001] The invention relates to the field of petroleum drilling, in particular to a method for calculating the well wall collapse pressure considering the pressurization effect stress. Background technique [0002] In the process of oil drilling, in order to prevent the wellbore from collapsing, it is necessary to calculate the minimum density of the drilling fluid in the wellbore to maintain the stability of the wellbore, that is, the collapse pressure. In oil and gas drilling operations, the wellbore collapse pressure value is one of the key supporting information for drilling safety, so it is very important to predict the wellbore collapse pressure. [0003] The calculation of existing wellbore collapse pressure is mainly based on the mechanical parameters of the rock itself, the in-situ stress of the wellbore rock and the original pore pressure. [0004] In the process of realizing the present invention, the inventor has found that there are at least the...

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Problems solved by technology

[0005] The existing wellbore collapse pressure calculation formula does not take into account the effect of drilling fluid on the rock wall during the drilling process, that is, during the drilling process, the drilling fluid filtrate invades the formation and forms mud cake on the wellbore wall, which will make the near wellbore zone The pore pressure increases, which in turn leads to an additional stress field in the wellbore formation, and changes in the force near the wellbore, making it difficult to accurately predict the collapse pressure with the existing formula for calculating the collapse pressure

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