A Prediction Method of Instantaneous Well Fluid Pressure in Perforation

Abstract

The invention discloses a perforation transient well fluid pressure prediction method. According to the perforation transient well fluid pressure prediction method, theoretical derivation, algorithm implementation and case analysis are combined, condition hypothesis is carried out based on perforation physical process analysis, and a one-dimensional model of a perforation wellbore pressure field is built; according to the change characteristics that well fluid pressure movement has the one-dimensional unsteady plane movement rule, the well fluid state and the gas state for pushing well fluid to move, underground relevant characteristic parameters are substituted in, well fluid pressure prediction is achieved through certain duration calculation, and well fluid pressure prediction passes energy conversation inspection. By means of the perforation transient well fluid pressure prediction method adopting physical modeling, numerical calculation and energy conversation inspection, the well fluid pressure peak prediction precision can be ensured, the change rule of pressure along with time is obtained, more useful information can be provided, and a theoretical foundation is provided for scientific perforation design.

Description

technical field [0001] The invention belongs to the technical field of prediction theories and methods in the petroleum perforation industry, in particular to a method for predicting instantaneous well fluid pressure in perforation. Background technique [0002] During the perforating operation, when the perforating gun is ignited, it often occurs that the perforating gun bursts and deforms, the interlayer gun squeezes and deforms, the tools in the delivery string are abnormally opened or damaged, the packer is automatically unsealed, and the negative pressure injection If the perforating process fails, the shock absorber or the perforating gun string will be impacted and broken in severe cases, causing serious and complex engineering accidents such as the gun string or tool string falling into the well. The direct cause of these engineering accidents is the energy change caused by the detonation of the perforating charge, a part of the energy is transferred to the well flui...

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Problems solved by technology

[0003] At present, there are generally two methods for predicting the well fluid pressure caused by the detonation of the perforating gun in China. One is the experience summarization method, which is to predict the well fluid pressure of the unconstructed well based on the test pressure data of the perforated well. When the well conditions change, the prediction accuracy is extremely low; another method is to apply commercial software modeling and analysis, the physical model of this method cannot be designed according to the actual situation, and the whole process lacks energy conservation verification, so it cannot Guarantee the accuracy of calculation results

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