气体钻井技术在新疆油田火北地区的应用

Application of Gas Drilling Technology in Huobei Area of Xinjiang Oilfield

火北地区为新疆油田致密油勘探的重要区域之一,该地区上部石炭系推覆体火山岩地层厚度大、可钻性差,机械钻速极低,为此尝试采用气体钻井技术来提高机械钻速。在采用三开井身结构设计方案的基础上,针对二开巨厚石炭系和深部二叠系地层的特点,从气体钻井实施井段地层理化特性、井壁稳定性、地层出水预测等方面对气体钻井进行适应性评价。研究表明,石炭系火山岩地层蒙脱石含量较低,地层稳定性相对较好,具备实施气体钻井条件,但在底部近断层存在出水的可能;二叠系地层黏土矿物含量相对较高,其坍塌压力也同时增高,实施气体钻井存在潜在的风险。此外,还制定了气体钻进施工、气液转换等技术措施。实钻表明,在石炭系、二叠系地层采用气体钻井工艺后提速效果显著,这为火北地区钻井施工提供了一条新的途径。

The Huobei Area is one of the important areas of tight oil exploration in Xinjiang Oilfield.In this area,the upper carboniferous napped volcanic rock stratum is thick,poor drillability,low penetration rate,therefore it attempts to use gas drilling to speed up the ROP.Based on the bore hole structural design schemes and the characteristics of thick Carboniferous &deeper Permian strata,it evaluates the adaptability from the physical and chemical characteristics in gas drilling section,borehole stability,formation water prediction.The research shows that montmorillonite content of the carboniferous volcanic rock strata is low and the formation stability is relatively good,it has the conditions for gas drilling,but water may be produced on the bottom of the near-fault;the clay mineral content is relatively high in Permian Formation,at the same time its collapse pressure also increases,it exists potential risk for gas drilling.Meanwhile it sets up some technology measures of the gas drilling operation and gas-liquid conversion.Actual drilling shows that it can improve the drilling speed obviously by using the gas drilling technology in the Carboniferous and Permian strata,and it also provides an effective way to speed up the development of the exploration in this district.