辽河油区东部凹陷火成岩深探井快速钻井技术及应用

Research and Application of Faster Drilling Technique in Deep Exploratory Wells in Igneous Rocks of Eastern Sag in Liaohe Oilfield

辽河油区东部凹陷火成岩油藏开发始于1971年,1998年以来先后发现黄沙坨、欧利坨等火成岩油气藏,现今已经成为东部凹陷勘探开发主要目的层。辽河油区东部凹陷火成岩油气藏的岩石物性、埋藏深度、含油气情况和地温变化等性质变化较大,在钻井施工中存在局部油藏压力高、井控风险大,井漏、井塌以及机械钻速低、钻头行进尺寸小等难点。通过对地层岩石物性的研究,确定了地层岩性特征、孔隙度和渗透率的取值范围、地层岩石硬度范围和可钻性级别以及适合的钻头型号,为钻井液选型和性能优化、钻头选型优化,以及工程事故和复杂情况的预防技术措施提供了依据。据此形成的辽河油区东部凹陷火成岩深探井快速钻井技术模板,应用于新施工井中,中完井深明显比老井深250~500m,钻井周期和建井周期都大大缩短。

Igneous reservoirs in the eastern sag of Liaohe oilfield were developed from 1971. Huangshatuo and Oulituo and other igneous reservoirs have been found one after another since 1998,which have been the main target strata of exploration and production in the eastern sag.In the drilling process,there are many difficulties ：high pressure in partial reservoir,great risk of well control,lost circulation,hole collapse and low penetration rate and small marching of the bit for great changes of various properties on physical property of rocks,burial depth,hydrocarbon-bearing condition and subsurface temperature in the igneous reservoirs of the eastern sag in Liaohe oilfield.After the research on the physical property of the rocks in the formations,lithology feature of the formations is known with known range of porosity and permeability,and suitable bit mode is fixed according to the known formation rock hardness and drillable grade.It provides basis for drilling fluid type selection and behavior optimization,bit type selection and optimization,and preventive safety for engineering accident and complex conditions.Faster drilling technique model for the deep exploratory wells of the ig-neous rocks in the eastern sag of Liaohe oilfield is formed and is applied to new wells.Intermediate comple-tion depth is deeper 250-500 m than the old well depth obviously,and drilling cycle and well construction period are shortened.