Integrated Steering Drilling Technology for Geology Engineering of Shale Gas

In order to best tap the potential of shale reservoirs and optimize the placement of horizontal wells during exploration and development, an integrated steering drilling technology was researched and developed in this paper. First, after an in-depth understanding of the shale reservoir was achieved, a high-resolution 3D fine geologic model was developed that could accurately predict "sweet spots". Second, optimization design was conducted on the well trajectory on the basis of the formation parameters extracted from the 3D geologic model. Third, microstructure change of target zones was ascertained by using reservoir prediction technologies, so as to provide the geologic basis for the well trajectory prediction. Fourth, the position of the bit was predicted in the hole accurately by means of geological target tracking and trajectory adjustment technologies. And finally, real-time modification was conducted on the geologic model by estimating the real formation dip, so that the well trajectory could be extended reasonably in the reservoirs. The technique was applied in Well NH2-4 during the drilling of its horizontal section. And based on the technique, it was 35.00 m from the horizontal section to bottom boundary of high-quality shale, and the corrected formation dip was 6.48°. The geological model was real-time modified and the trajectory parameters were adjusted for time, so high quality reservoir drilling rate achieved 94.5%. It is shown that the integrated steering drilling technology for geologic engineering provided apractical and feasible integration technology for the development of shale gas.