Pressure-controlled drilling method based on drilling annulus wellbore multi-phase flow computing

Abstract

The invention relates to a pressure-controlled drilling method based on drilling annulus wellbore multi-phase flow computing, which comprises the following steps: obtaining basic parameters for drilling wellbore multi-phase flow computing; determining the variety of fluid in wellbore annulus; considering multi-phase multi-component complex flow factors, and establishing a wellbore annulus internal multi-phase flow control equation group; establishing definite conditions for the multi-phase flow control equation group by combining with technical processes under pressure-controlled drilling different working conditions; carrying out grid division on the time and space domains obtained by multi-phase flow computing; carrying out numerical discretion; solving the wellhead back pressure required by pressure-controlled drilling; and adjusting the wellhead throttling valve based on the computed wellhead back pressure value to realize pressure-controlled drilling. Through the adoption of the method, pressure-controlled drilling can be continued under the condition that the drilling fluid contains gas; the method can be applied to the pressure-controlled drilling process of strata highly containing acidic gases; and the computation accuracy is high, the error is small, the control accuracy of pressure-controlled drilling is improved, and the application range is enlarged.

Description

technical field [0001] The invention belongs to the field of oil and gas field development, and in particular relates to oil and gas drilling wellbore pressure control, in particular to a method for controlling pressure drilling. Background technique [0002] As the scope of oil and gas exploration continues to expand, the formation conditions encountered in drilling are becoming more and more complex, and complex situations such as lost circulation, pipe sticking, and well wall collapse frequently occur in drilling engineering, especially for fracture pressure and pore pressure windows. In narrow formations where blowouts coexist, the frequent occurrence of downhole accidents greatly increases the non-production time and pushes up the cost of drilling operations. At the same time, three-low (low resistivity, low porosity, and low permeability) complex oil and gas reservoirs have become an important part of resource replacement. The characteristics of these oil and gas reser...

AI Technical Summary

Problems solved by technology

However, the signals of APWD / PWD downhole measuring instruments mostly rely on mud pulses. When the drilling fluid is mixed with gas, the signals cannot be transmitted to the ground normally, and MPD cannot be carried out normally.

At the same time, APWD / PWD downhole pressure measuring instruments are mostly monopolized by a few technical service companies, which only provide high-priced services and do not sell products, which restricts the development of controlled pressure drilling technology to a certain extent

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