渤海油田变质岩潜山油藏钻井关键技术

Key Drilling Technologies for Metamorphic Buried Hill Reservoirs in Bohai Oilfield

渤海油田某潜山构造的深部变质岩潜山具有巨大的成藏潜力,但该构造地质条件复杂,目的层较深,钻井面临机械钻速低、储层保护难度大、井壁失稳和漏失风险高等技术难点,为此,进行了钻头及提速工具优化设计、井壁稳定技术、储层保护技术、螺杆钻具优化、防漏堵漏技术等方面的研究,形成了渤海油田变质岩潜山油藏钻井关键技术。该构造的7口探井应用了该技术,克服了该构造存在的技术难点,机械钻速得到提高,其中3口探井获得高产油气流。研究和现场应用结果表明,渤海油田变质岩潜山油藏钻井关键技术可为渤海油田深层变质岩潜山油气藏的勘探开发提供技术支持。

A deep metamorphic buried hill in Bohai Oilfield has a great potential for hydrocarbon discoveries.However,complicated geological tectonic conditions and deeply buried target zone create a series of drilling challenges such as low rate of penetration(ROP),difficult reservoir protection,and high risk of wellbore instability and leakage.To solve the problems,a study was created to evaluate the optimization of drill bits and ROP improvement tools,wellbore stability technologies,reservoir protection technologies,positive displacement motor(PDM)optimization,and leakage prevention and plugging technologies.As a result,key drilling technologies for metamorphic buried hill reservoirs in Bohai Oilfield were developed,which were then successfully applied in seven exploration wells in this buried hill structure.As a result,the technical difficulties of the structure were overcome,i.e.,the ROP was increased,and three exploration wells obtained high oil flow.The research and field applications indicate that the key drilling technologies can provide technical support for the exploration and development of deep metamorphic buried hill reservoirs in Bohai Oilfield.