Fast and fine geological orientation method for shale gas horizontal well

Abstract

The invention relates to a fast and fine geological orientation method for a shale gas horizontal well. Materials are collected, an orientation comparing standard well and a reference well are determined, and an orientation sign layer and a target spot predicting scheme are determined; a well zone two-dimensional geological orientation model and a well zone three-dimensional geological orientation model are built and regulated, and a two-dimensional vertical section and the three-dimensional geological orientation model of a well to be oriented are amended in time; by means of the characteristics of lithological characters, well deflection, while-drilling gamma and the like of the well to be oriented, the standard well and the reference well, stratum comparing is conducted; the position where a drill is located is judged through three figures, one table and the like; whether the position where the drill is located is in a high-quality shale gas layer section or not is evaluated while drilling; whether an initial geological model is applicable or not is judged; through an equal-thickness comparing method a target spot A is determined and regulated, a target spot B is predicted, and a track of a borehole in a horizontal section is controlled; and the pass-through rate of a high-quality shale gas layer is calculated according to the statistic drilling-meeting thicknesses of a shale reservoir and a high-quality shale reservoir, whether the track is controlled to reach the target spot B or not is judged, and the fast geological orientation effect is evaluated. Fast orientation is achieved, the application range is wide, and application and popularization are easy.

Description

technical field [0001] The invention belongs to the technical field of horizontal well drilling for shale gas exploration and development, and in particular relates to a fast and precise geosteering method for shale gas horizontal wells. Background technique [0002] The currently popular geosteering method is mainly based on the comparison results of the drilled well data and the well to be steered to guide the drill bit to travel through the target interval. Geological modeling is mostly two-dimensional. The steering method is applicable to specific blocks or specific formations and is universal. Poor performance is not conducive to replication and promotion in other work areas. There is an urgent need to study a geosteering method that is easy to operate and easy to popularize and apply in the field in China. [0003] CN105464592A discloses a geosteering method for a shale gas horizontal well, which includes the following steps: according to the lithology and electrical c...

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Problems solved by technology

[0002] The currently popular geosteering method is mainly based on the comparison results of the drilled well data and the well to be steered to guide the drill bit to travel through the target interval. Geological modeling is mostly two-dimensional. The steering method is applicable to specific blocks or specific formations and is universal. Poor performance, which is not conducive to replication and promotion in other work areas. There is an urgent need to study a geosteering method that is easy to operate and easy to popularize and apply in the field in China.

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