A shale gas horizontal well landing trajectory tracking and control method while drilling

Abstract

The invention provides a tracking-while-drilling controlling method for a landing track of a shale gas horizontal well. According to a stratum inclination angle in the track construction direction, the vertical thickness of the well is combined and compared, the vertical distance from a kickoff point to the top of a target body is calculated and a well track is designed; well inclination is distributed and is adjusted in time, then an inverse method is adopted; and well inclination data corresponding to every stratum marker bed is determined as a landing practical drilling track controlling basis. When the practical drilling track drills to a characteristic point of the gamma curve, the practical drilling well inclination is matched with the characteristic point designing well inclination and then construction is conducted according to the designed track; the practical drilling inclination is not matched with the characteristic point designing well inclination, track parameters are calculated and the track is smoothened in order that the next characteristic point and design can meet the requirement of matching with each other until the landing construction is finished. The landing well hole track formed by the tracking-while-drilling controlling method is smooth; the friction resistance of the landing well region is reduced effectively; drilling speed is improved; it is guaranteed that the well hole track can extend smoothly and the risk of the horizontal well construction operation is reduced.

Description

technical field [0001] The invention belongs to the technical field of shale gas development, and in particular relates to a method for tracking and controlling the landing trajectory of a shale gas horizontal well while drilling. Background technique [0002] The shale gas drilling operation in Sichuan generally adopts the factory drilling construction mode, that is, due to the limitation of terrain conditions, several horizontal wells are deployed within the limited range of the same platform on the ground, and they are respectively constructed in different directions. The spacing is to reach the maximum downhole reservoir control area of ​​the well group, the drilling trajectory is generally medium to long radius, and the landing section is designed with a three-dimensional trajectory. In order to meet the requirements of high borehole curvature for 3D trajectory, rotary directional tools and logging while drilling tools (MWD) with high build-up rate are generally used in...

AI Technical Summary

Problems solved by technology

In formations with complex structures, frequent changes in formation dip angle, and unstable lateral characteristics, the well deviation of the trajectory will be large and the landing will not be possible, or the well deviation will be too small. Large, difficult construction in the horizontal section and later completion operations, low drilling rate of effective reservoirs, etc.

At the same time, in order to enter or return to the target body as soon as possible, the well deviation of the trajectory is greatly adjusted, resulting in the unevenness of the wellbore trajectory, increasing the frictional resistance between the drilling tool and the well wall, and increasing the difficulty for subsequent construction. The reservoir drilling rate in the horizontal section also affects the completion of the footage in the horizontal section, which may easily cause downhole complexities such as stuck pipe, sidetracking in filling holes, and difficulties in lower oil layer casing.

In addition, the rotary directional tool is expensive in price and use, the landing trajectory is not smooth, and the friction is large, which can easily shorten the service life of the equipment and cause damage to the equipment. In addition, its poor salvageability after the occurrence of downhole complexities creates a high economic risk

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