Directional well drilling process used for mudstone section

Abstract

The invention discloses a directional well drilling process used for a mudstone section and belongs to the field of directional wells. A directional well vertical well section drilling assembly of theprocess comprises a drill bit, a hydraulic pressurizer, a non-magnetic drill collar, a drill collar, a drill rod and an MWD wireless while-drilling inclinometer which are sequentially connected, wherein the MWD wireless while-drilling inclinometer is fixed into the non-magnetic drill collar. A whipstocking drilling assembly comprises a drill bit, a single bent screw, a hydraulic pressurizer, a non-magnetic drill collar, a drill collar, a drill rod and an MWD wireless while-drilling inclinometer which are sequentially connected, wherein the MWD wireless while-drilling inclinometer is fixed into the non-magnetic drill collar. An angle holding drilling assembly comprises a drill bit, a straight screw, a hydraulic pressurizer, a non-magnetic drill collar, a drill collar, a drill rod and an MWD wireless while-drilling inclinometer which are sequentially connected, wherein the MWD wireless while-drilling inclinometer is fixed into the non-magnetic drill collar. A well drilling fluid comprises 3-4% of bentonite, 0.7-1.0% of filtrate-loss reducers, 0.7-1.2% of fluid loss agents, 0.2-0.4% of acidity control agents, 2-4% of temporary plugging agents, 3-5% of lubricating plugging agents, 2-3% of solid lubricating agents and the balance water. According to the directional well drilling process used for the mudstone section, flexible pressurizing during well drilling can be achieved, goodshock absorption is achieved, deviation-prevention rapid drilling is achieved, and the back pressure phenomenon is prevented.

Description

technical field [0001] The invention relates to the field of directional wells, in particular to a directional drilling technique for long mudstone sections. Background technique [0002] In the process of petroleum exploration and development, in order to avoid insurmountable ground obstacles, increase the exposed area of ​​oil and gas layers in the wellbore, and increase the production of oil wells, directional wells of a certain length are usually drilled in the oil and gas layers. Directional well refers to a well that is drilled to reach the target layer along the pre-designed well trajectory and deviates from the vertical line of the wellhead by a certain distance in a predetermined direction. According to the shape of the wellbore trajectory, the directional well can be designed into two-dimensional directional wellbore trajectory, three-section wellbore trajectory, S-shaped wellbore trajectory, parabolic wellbore trajectory, horizontal wellbore trajectory and so on. ...

AI Technical Summary

Problems solved by technology

[0005] For the mudstone section, due to its geological complexity, the drilling tool assembly provided by the existing technology is used to carry out directional well construction on it, which has problems such as slow drilling speed, severe back pressure, easy to cause well collapse accidents, and low well quality pass rate

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