胜利低渗油田长水平段水平井钻井关键技术

长水平段水平井钻井技术已经成为低渗透油气田开发的重要技术保障,但国内相关技术起步较晚,对该项技术的认识还需要统一,对如何发展与该技术配套的优快钻井技术有待进一步研究。通过分析该技术在井眼轨道优化设计、井眼轨迹控制和钻井液性能提高方面的主要技术难点,明确了关键技术攻关方向。通过模拟分析井眼轨道摩阻、扭矩,确定了造斜率和井眼轨道类型的优选原则;通过分析靶前位移与裸眼段摩阻系数的敏感性,明确了二者关系,并就其成因进行了钻柱力学解释,提出了靶前位移的优选原则,形成了长水平段水平井井眼轨道设计的主要思路。建立了基于地层可钻性级值的井眼轨迹控制方案优化方法,提出了以旋转减摩技术为基础的井眼轨迹高效控制思路。梳理了井壁稳定、井眼净化和润滑防卡等长水平段水平井钻井液关键技术,介绍了相应的主要技术措施。结合高平1井,介绍了上述各关键技术的应用情况,实例验证了各技术的有效性。 

Key Drilling Technologies for Long Displacement Horizontal Wells of Low Permeability Reservoirs in Shengli Oilfield

Drilling long displacement horizontal wells has become an important technical support to develop low permeability reservoirs,but related techniques in China start relatively late.It is necessary to reach a common understanding of the techniques and carry out further research on optimized match drilling techniques.Therefore,the key-point of the technique has been identified by analyzing their difficulties in well trajectory design and control as well as drilling fluid properties.The principles for selection of build-up rate and well trajectory type have been set up through simulating torque and drag.Through analyzing sensibility of friction coefficient and displacement from well head to target point,the main characteristics and their relationship have been determined,the corresponding explanation of drilling string mechanics was given,the selection principle of displacement from well head to the target point was proposed,the main idea for well trajectory design of long displacement horizontal well formed.An optimized well path control solution was established on the basis of formation drillability grades,and then an effective well path control method was presented by rotary reduction of friction.The critical techniques of wellbore stability,hole cleaning and anti-stick lubrication were sorted out and introduced.Well Gaoping 1 is taken as an example to illustrate the above techniques and their effectiveness.