井底压力条件下岩石可钻性实验及仿真研究

The Experiment of Rock drillability and Simulation Research under the Condition of Bottom Hole Pressure

岩石的可钻性是正确评价是确定钻井参数、选择钻头类型、预测钻井效果以及规定钻进工作定额时所必需的;而以往岩石可钻性极值的确定都是在常压下进行的。常压下岩石的可钻性极值与井底压力条件下岩石可钻性极值相差较大,远不能满足工程需要。为此,提出了一种室内测定井底压力条件下岩石岩石可钻性极值的实验方法;并通过HyperMesh有限元处理器仿真得到井底压力条件下岩石的可钻性极值的仿真值。通过对实验数值和仿真数值的对比,二者误差都在10%以内。所以该实验方法能够较准确的得到井底压力条件下岩石的可钻性极值。从而更能够准确的选择钻头类型,优化钻进参数,指导工程实践。

The drillability of rocks can provide correct evaluation and drilling parameters for bit selection,the prediction of drilling performance. In the past,the extreme value of rock＇s drillability can be determined at the normal pressure conditions. However,there is the bigger value gap between normal and bottom hole pressures. As the result,the determination of rock drillability extreme value is carried out under conditions of atmospheric bottom hole pressure. Otherwise,the simulation extreme value of rock drillability can be obtained by HYPERMESH finite element simulation. Compare experiment data with simulation,the deviation between experimental data and simulations are less than 10%. Therefore,this method can obtain accurately extreme value of rock drillability under the bottom hole pressure. Finally,there are more accurate results for bit types,optimizing drilling parameters,and guiding engineering practices better.