Optimization Design And Application Of Multi-branch Horizontal Well Drilling Engineering In Zhengzhuang Block

As a new type of clean energy,coal-bed methane has been paid more and more attention.It is also an important research topic to choose suitable drilling methods for the exploitation of coal-bed methane.The coal seam is located in Zhengzhuang Block of Qinshui.It has the characteristics of shallow buried coal seam,slight changes in stratum,stable top mudstone structure,moderate development of coal rock fracture and high gas volume.After the analysis on the applicable conditions of multilateral horizontal wells and the comparison about the gas production data between single and Multi-branch horizontal well,this paper has drawn a conclusion that the Multi-branch horizontal well is more suitable for the development of coal-bed methane in Zhengzhuang Block.Then,by analyzing the drilling technology and technical difficulties of multi lateral horizontal wells,this paper explains in aspects of well structure,trajectory design and drilling assembly.By selecting suitable coalbed methane production model,the optimal horizontal length and branch shape suitable for Zhengzhuang block condition are obtained.Combined with the characteristics of different construction sections,the selection of drilling tools in each section is optimized,and a set of construction plan of the block is worked out.Ultimately taking the case for ZP-6H well,its well structure,well trajectory and drilling tool combination will be optimized the design.Comparing and analyzing the actual drilling situation with the design of the well,the conclusion drawn from the empirical conclusion is of guiding significance for the construction of Multi-branch horizontal well in Zhengzhuang block in the future.