A Directional Drilling Technology 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 process for long mudstone sections. Background technique [0002] In the process of oil exploration and development, in order to avoid insurmountable ground obstacles and increase the exposed area of ​​the oil and gas layer in the wellbore to increase the output of the oil well, a certain length of directional well is usually drilled in the oil and gas layer. A directional well refers to a well that is drilled to the target layer along the pre-designed wellbore track and deviates from the vertical of the wellhead by a certain distance in a predetermined direction. According to the shape of the borehole trajectory, the directional well can be designed into a two-dimensional directional well bore trajectory, a three-section well bore trajectory, an S-shaped borehole trajectory, a parabolic bore trajectory, a horizontal borehole trajectory, and so on. For mudstone...

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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