伊朗Y油田深部复杂地层钻井液技术

Drilling Fluid Technology for Deep Troublesome Formation of Y Oilfield in Iran

伊朗Y油田深部地层的超厚活跃沥青层和高压差储层钻进过程中,存在沥青侵入、压差卡钻事故频发和Φ149.2mm井眼地层压力测试困难等问题。在室内试验的基础上,对钻井液的封堵、润滑和抑制防塌等关键性能和相关技术措施进行优化;利用选择性优先粘附和稠化封堵技术措施,有效控制了Kazh地层的沥青侵入程度;在保证钻井液具有良好的封堵和润滑性能的基础上,分段采用强化封堵技术措施有效解决了FLN地层压差卡钻的问题。现场应用表明,FH4井、FH14井和FH17井均实现了28MPa高压差下的安全施工。

Drilling in deep formation in Iran Y Oilfield, which contains ultra-thick active bitumen and high differential pressure, is facing challenges such as bitumen invasion, differential sticking, difficulty in formation pressure test at 149.2 mm hole section, etc. Therefore,on the basis of laboratory study, the key properties of drilling fluid including plugging, lubricity, inhibition and slough-prevention were optimized. The bitumen invasion was controlled by selective preferential adherence and thickening and plugging tech nology in Kazhdumi Formation. Apart from keeping good plugging and lubrication of drilling fluids, separa- ted layer sealing technique was applied in Fahliyan Formation to overcome the sticking caused by differenti al pressure. All these measures that were applied in Well FH4, FH14 and FH17, solving bitumen invasion and differential sticking are effective. There was no trouble and complicated situation happened during drill- ing operation in high differential pressure （28MPa） formation.