井下固控装置的研究及应用

Drilling speed raising technology research and application by downhole solid control device

在钻井过程中,为保障钻井安全需在钻井液中加入大量固相颗粒,钻井液中固相颗粒对机械钻速的影响较大,研制了一种安装在钻头上方的井下固控装置,该装置通过水力旋流分离原理将钻井液中大部分固相颗粒与钻井液分离并甩入环空区域,使通过钻头的钻井液固相含量大大减少。本装置设计的排固喷嘴有反向喷射作用,可以实现高效清洗井底,提高机械钻速。通过室内分离效果试验确定了装置的锥体角度和最优排量。在胜利油田、胜利海洋钻井进行了现场应用,验证了该装置安装方便,工作可靠,有明显的提速效果,可降低钻井液中的固相含量并有利于提高机械钻速。

In oil and gas reservoir drilling,a large number of solid particles are added into the drilling fluid to ensure the securityof drilling.Statistics show that the mechanical drilling rate will decrease as the solid content in drilling fluid increases,and the solidcontent in drilling fluid will increase with the grow of well depth.To reduce the influence of solid content in drilling fluid on the rate ofpenetration,the paper proposes a downhole solid control device which is mounted above the bit.Using the hydraulic cyclone separationmethod,it can separate most of the solid particles and drilling fluid,and slam them into the annulus area.In this way,the solid contentof the drilling fluid flowing through the bit can be greatly reduced.The solid discharge nozzle of the device has a reverse jetting effect,which can effectively clean the downhole wellbore and increase the mechanical drilling rate.The cone angle and optimal delivery capacityof the equipment are determined through separating effect laboratory experiments.The device has been tested in Shengli onland fieldand Shengli offshore field,verifying that reducing the solid content of the drilling fluid can help improving mechanical drilling rate.Theequipment features easy installation,reliable operation,and obvious acceleration effect.