也门32区块Tasour-5井钻井液技术

Drilling fluid technology for well TASOUR-5 in Yemen block 32

Tasour-5井是中原油田在也门32区块为挪威DNO/DOVE公司钻的1口定向探井,定向垂深为1850 m,井斜42°,水平位移为798 m。完井测试产油量为800 m/d。也门32区块上部地层坚硬,石灰岩裂缝发育,漏失严重;下部地层以石灰岩、泥页岩、砂岩为主,地层疏松,易漏失,属低压高产地层。上部地层采用空气锤/泡沫钻井技术,解决了该地层的漏失问题,泡沫钻井液的主要添加剂为碳酸钠、烧碱、HV-CMC、PAC-R和发泡剂;下部地层采用PHPA钻井液体系,钻井过程中用XCD聚合物和LCM堵漏剂对钻井液进行维护处理,使井径规则,井干净,有效地防止了地层坍塌和卡钻事故的发生。结果表明,泡沫钻井液和PHPA钻井液体系性能稳定,流变性能好,具有很强的防漏、防塌能力,润滑性好,滤失性和携砂能力强,维护简单,有效地保护了油气层,满足了该地区钻井施工的要求。

Well TASOUR-5 is a directional exploratory well drilled for DNO/DOVE Norway company on block 32 in Yemen, with a TVD of 1850 m, hole inclination of 42°and horizontal displacement of 798 m. The upper formation in block 32 is consisted of fractured limestone, serve lost circulation can be encountered. The lower formation is consisted of loose limestone, shale and sandstone, with low formation pressure coefficient. According to the formation characteristics, air/foam drilling was used in the upper interval of this well, and solved the problem of lost circulation. PHPA drilling fluid system was used in the lower interval, and XCD polymer and LCM material were added during drilling, which effectively prevented hole caving and pipe sticking from taking place, and made a regular and clean hole. Field using showed that the drilling fluid systems used in this well have stable performances, good rheology and lubricity, better filtration control and cuttings transportation, additionally, it is easy for maintenance and effectively protected formation.