Study on well path control technologies for pinnate horizontal CBM wells

Pinnate horizontal well technology is one of the main technologies for coal bed methane (CBM) development. It is very important to study on the well path control technology for increasing much more footage in coal seams and decreasing borehole problems. Based on the analysis of CBM generation mechanisms and characteristics of pinnate horizontal well, the flow chart of analysis on well path controlling for pinnate horizontal well and general controlling methods are presented. Besides, some well path control technologies such as log response controlling technology of resistivity-while-drilling and gamma ray logging, etc., and well path real time tracking and predicting in different dip angles of coal seams are also introduced in details. It comes to conclusions that one of the most important things for controlling well path is to master the accurate parameters for coal seams and strata dips, and to find out the lithologic characters of the adjacent rocks. It could implement the real time controlling and adjusting on the well path with the real time analyses of drilling parameters, resistivity, gamma ray logging, and so on, and it finally could ensure the bit drilling ahead along the optimum position of target zones.