A method for predicting formation collapse pressure and fracture pressure under the drill bit while drilling

Abstract

It relates to a method of predicting the collapse and crack pressure underground with the drilling head. Recording the earthquake status of a well to be drilled and several other adjacent drills that have already been drilled, getting the earthquake record of the well to be drill and already drilled through weighting, through sound wave echoing difference and density measuring for the already drilled wells to get the log data of different strata, a hierarchical model can be established to predict the sound wave speed and wave resistance of each strata based on the earthquake record. Through the log curve predicted of the strata of the well to be drilled, the collapse and crack pressure of the strata can be predicted combined with the interpretative model of the well wall stability mechanics logging. It can effectively prevent the collapse of the well wall and accidents occurrence underground.

Description

Technical field [0001] The invention relates to a method for predicting collapse pressure and rupture pressure while drilling, and more specifically, to a method for predicting the collapse pressure and rupture pressure of the formation under a bit by using seismic records while drilling. Background technique [0002] In the process of oil drilling, stress concentration occurs due to the formation of the wellbore. Too low or too high drilling fluid density in the well will cause the formation to collapse (reduction) or rupture of the borehole wall, resulting in complex downhole operations and prone to accidents. The manpower and material resources of drilling operations bring varying degrees of loss. [0003] Therefore, how to predict the collapse pressure and fracture pressure before drilling is very necessary, because if the collapse pressure or fracture pressure can be predicted before drilling, it can provide a scientific basis for drilling design to determine the safe drilling...

AI Technical Summary

Problems solved by technology

[0002] In the process of oil drilling, due to the formation of the wellbore, stress concentration occurs, and the density of the drilling fluid in the well is too low or too high, which will cause the well wall to collapse (diameter shrinkage) or rupture, resulting in complex downhole operations and prone to accidents. The manpower and material resources of drilling operations bring different degrees of losses

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