The Study On Drilling Techniques Of Coalbed Methane Horizontal Well In HanCheng Area

Coalbed Methane(CBM) , namely Coalbed Gas, is a new-born energy source in recent 20 years in the world. It is unconventional natural has which exists in coalbed by adsorptive state. In our country, the resource of CBM which depth low than 2000m is about 31.46×1012m3, which is the same quantity as nuatural gas's reserves. The recent exploration statistics tells,in HanCheng target area,there is a great number of CBM stored in coalbed. But because of coalbed's low pressure, low penetration, low saturation and high absorption, vertical well widely used hardly reaches its expected business value on exploration.. Therefore,in addition to investigation of HanCheng coalbed characteristics, have to combined with current horizontal well project experiences,we should develop the most proper coalbed gas horizontal well drilling technology .First,this article starts with the analysis of HanCheng area coalbed,studied on coalbed gas's characteristics and pressure , analyzed reservoir property and pore structure, given proofs to support formation damage analysis and for drilling design and construction.Then, on the basis of worldwide horizontal well techniques study,especially JinCheng's techniques,this article mainly investigates research techniques for HanCheng area,which contains:confirming research area horizontal well's well body structure; design and calculation of path,drilling tool choices and matching drilling parameters,accord to different part of well given ways to control path, stabilizing borehole, and reservoir protection,etc.This paper supports the Horizontal Well design in research area,and supports the efficient use of horizontal well drilling technology in HanCheng,actively stimulates the output of coalbed gas.