Trona deep and thin layer multi-connected horizontal well borehole track control method

Abstract

The invention discloses a trona deep and thin layer multi-connected horizontal well borehole track control method. The trona deep and thin layer multi-connected horizontal well borehole track control method is characterized by comprising the following steps of (1) optimal design of double-connected horizontal well track sections; (2) application of an error correction technology; and (3) application of an LWD and RMRS fused measurement and borehole track accurate control technology. The design problem of the deep-layer double-connected horizontal well track sections is solved; a conventional LWD measurement instrument is adopted, an RMRS measurement technology is introduced, acting as a go-between is achieved through precise control over borehole tracks, two vertical well boreholes with the diameters being 118 mm and 105 mm are connected at one stroke at the positions with the vertical depth being 2981 m and 3013 m and the slant depth being 3239.5 m and 3512.6 m, and point-to-point butt joint is successfully achieved.

Description

technical field [0001] The invention belongs to the technical field of trona mining, and in particular relates to a method for controlling the wellbore trajectory of a trona deep thin layer multi-connected horizontal well. Background technique [0002] Directional butt joint well connection technology is a special technology developed in recent years. At present, it is mainly used in the exploitation of soluble well mineral resources and coalbed methane in my country. It adopts directional well and horizontal well technology to make two or more wellbores directional butt connected at a certain depth underground, hundreds of meters or even thousands of meters apart, so as to realize the technology of multi-well connection and high-efficiency mining. With the advancement of directional horizontal well technology and measuring tools and instruments, it is possible to connect the wellbore with each other, and it has been widely popularized and applied in high-efficiency mining i...

AI Technical Summary

Problems solved by technology

[0006] 2. High requirements for precise control of wellbore trajectory:

Two vertical wells are connected at a depth of about 3000 meters, and the boreholes of the two vertical wells are small in diameter, Φ118mm and Φ105mm respectively, and the wells are connected point-to-point precisely; the vertical well is deep, and the cumulative error of the borehole data is large, and the accuracy of the data directly determines the energy If there is no one-time connection, the target data error is large, and the trajectory adjustment cannot be realized, which will cause connection failure, and a certain distance needs to be backfilled to sidetrack;

[0008] 3. The wellbore of the connected target is small and the connection is difficult:

[0009] From the point of view of reducing the difficulty of connection between point A and point B of the two connected target vertical wells, the diameter of the solution cavity should be increased to more than half a meter after the construction of the groove (expansion chamber), which is more conducive to the "point-to-point" connection between the two wells; but after the construction of the groove If the dissolution cavity is too large, it will be unsafe downhole when crossing point A, and it is easy to encounter obstructions, etc. Therefore, no trench (expansion cavity) is built, and the newly drilled Φ216mm hole is directly connected to the already drilled Φ118mm and Φ105mm wellbore. The target point is too small. "Point-to-point" connection construction is difficult