Method for evaluating simulation of full-size well wall stability

Abstract

The invention discloses a method for evaluating simulation of full-size well wall stability. The method includes utilizing a full-size well wall stability simulator to apply confining pressure, pore pressure, horizontal pressure, overburden pressure, mud circulating pressure and drilling fluid circulating mediums required by an experiment on a rock core; measuring diameter expanding conditions of a rock core well in the process of the experiment through a well diameter measuring instrument (19); measuring acoustic wave feature changes of rock samples at a well wall after being soaked by drilling fluid under different circulating media in the process of the experiment through a stratum sliding wave sound speed testing system; directly observing actual changing conditions of the well after the well wall is soaked by the drilling fluid through a well wall visualizing and imaging system. The method has the advantages that downhole high-temperature high-pressure environment can be simulated more truly, stability conditions of the well wall can be evaluated dynamically, wellhole circulating media can be changed, the stability conditions of the well wall under different drilling modes can be evaluated, optimization of the drilling modes and drilling fluid systems is facilitated, and the method has high practicability and is convenient for popularization.

Description

technical field [0001] The invention relates to the technical field of simulation research well wall stability experiment evaluation methods in the exploration and development of oil and gas fields, in particular to an evaluation method for simulating full-scale well wall stability. Background technique [0002] The wellbore instability problem is a common problem in the exploration and development of oil and gas fields and has always been a big problem in the petroleum industry. Well wall instability seriously affects the speed, quality and cost of drilling. According to conservative estimates, well wall instability will cause a loss of 500-600 million US dollars to the world oil industry every year, and the drilling fluid will immerse into the oil industry due to well wall instability. In the reservoir, the reservoir is polluted, which has a negative impact on the exploitation of oil and gas fields, which seriously restricts the process of exploration and development. The...

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Problems solved by technology

However, these instruments cannot simulate the real high temperature and high pressure downhole mechanical environment, cannot comprehensively evaluate the impact of different drilling methods on the stability of the borehole wall, cannot comprehensively evaluate the performance of drilling fluid, rock acoustic characteristics and formation permeability, and the measurement parameters are limited and cannot be intuitive Response to Situation After Borehole Wall Instability

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