Study on driling/cementing technique affected to production control of coalbed methane vertical well

in order to optihmize the coalbed methane well riling and cementing technical parameters according to the production data,friing and cementing information of 71 coalbed methane verical wels in Fanzhuang Block at the south part of Qinshui basin.the paper discussed the density and viscosity of thed ilig liuid .thedensity and amount of the cemert grout for the el cemening and the replacement liquid anounto the control mechanism ofthe producion capacity Theresultshowed that when the densty of the driling liuid was less than 1.05 glcem-3,the viscosity was less than 30 s ,the cement grout densityof the well cementing was less than1.85 gicmn-3,anount of the cement grout for the well cementing was less than 22.5 m -3 and the displacement fuid volme wa less than 10.0 m~-,.the calbed methane well could have a high production.A high density ofthe drllig louid and thecement grout for the wel cemening a high desity of rlng licuid as well as a high volume of cementing cement grout and replacemeant licuid all woud cause the solid media accunulation in the pores and cracks of the coal reservirt, he pemeability redu.ed and would not be favorable to the water discharging pressure drop and coabed metane output.Wwith the inegration with the drlling and cementing techniques ffected to the production capacity of the caled methane wel. he opimized drlling and cementing technical paramerers were provided and could provide the references tothe drilling and cementing engineering implemented and the coal reservoir protection.