Research On The Application Of Casing Valve During Underbalanced Drilling Operations In Liaohe Oilfield

Casing valve is able to meet the needs of the whole-process underbalanced drilling horizontal wells, side tracking wells and the branch wells, reduce the risks in the process of tripping drill with pressure in conventional underbalanced drilling , save the time of tripping drill, reduce Environmental pollution caused by the waste drilling fluids, reduce the possibility of drilling accident occurred. It is gradually being more oil companies. In order to facilitate the development of the whole-process underbalanced drilling technology in the Liaohe region, we optimize the casing valve type on the basis of the geological characteristics of reservoirs in Liaohe Oilfield, study the construction of the valve casing on the basis of the indoor simulation and the successful drilling opretion. The main contents and outcomes are as following:1,Xingma Guqianshan, Chenjia Guqianshan and Maquanzi Guqianshan in Liaohe Oilfield was studied as the main objects, we summ up the the formation of a single, good stability and reservoir without H2S as the characteristics of t the Liaohe oilfield. The use of casing valve in the whole-process underbalanced drilling is easier to find Guqianshan section of low pressure, low permeability reservoir than the use of conventional underbalanced drilling.2,Analysis the structure and the mechanism of the casing valve, combine with the geological characteristics of Liaohe Oilfield ,calculate the method of determining the depth of the casing valve, and develop a casing valve technology construction in the process of drilling without overflow, drilling overflow and tripping drill to control the process pressure.3,On the basis of the indoor simulation of the casing valve technology process and the successful opretion of Magu 11 well, An 1-H8 well Chengu 1-1 well, we summ up a set of practical operation of the casing valve technology.The studies targeted casing valve in this paper, provide support for the development of the whole-process underbalanced drilling technology in Liaohe Oilfied. There is really important and practical significance for raising the oil and gas production in Liaohe Oilfield.