Saline Layer Pressure Relief Methods

Abstract

The invention provides a method for relieving the pressure of a brine layer. The method comprises the following steps that a well is closed when well drilling fluid overflows, and the brine intrusioncapacity limit value in the preset time period when the well drilling fluid begins to overflow is determined; after the well is opened, the displacement of the well drilling fluid is adjusted by adjusting the return pressure, and the density of the well drilling fluid is lowered, so that the brine intrusion amount in the preset time period is controlled to be smaller than or equal to the brine intrusion capacity limit value. The method for relieving the pressure of the brine layer can effectively avoid a series of problems caused by high pressure entrapment of the brine layer, leakage and overflow of a shaft are effectively controlled, the safety of the shaft is improved, the well drilling success rate of the super-high-pressure brine layer is improved, and the well drilling success rate is increased.

Description

Technical field [0001] The invention relates to petroleum exploitation technology, in particular to a method for releasing pressure from a saltwater layer. Background technique [0002] For oil exploration areas with huge thick salt-gypsum layers with complex geological characteristics, salt-gypsum layers are distributed in the salt-gypsum layers. However, the saline layer is irregularly distributed vertically and vertically, and there is no marking layer before the saline layer is drilled, making it difficult to accurately predict the saline layer. [0003] During the drilling process, the brine layer will form a high-pressure trap for the drilling, and the high-pressure trap of the brine layer will cause the brine to invade the wellbore and contaminate the drilling fluid. At the same time, the brine will precipitate crystalline salt after reaching the wellhead, which is easy to block the wellhead annulus and the ground Manifold. [0004] How to solve a series of problems caused b...

AI Technical Summary

Problems solved by technology

However, the vertical and horizontal distribution of the saline layer is irregular, and there is no marker layer before the saline layer is drilled, making it difficult to accurately predict the saline layer.

[0003] During the drilling process, the brine layer will form a high-pressure trap for drilling, and the high-pressure trap of the brine layer will cause brine to invade the wellbore and pollute the drilling fluid. At the same time, when the brine reaches the wellhead, crystallized salt will be precipitated, which is easy to block the wellhead annulus and the ground Manifold

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