致密气藏井间干扰程度评价新方法

A new method for evaluating the degree of well interference in tight gas reservoirs

井网加密是提高致密气藏采收率的有效措施,准确评价井间干扰程度是井网加密的基础。联立定产致密气井的产能方程、渗流力学方程和物质平衡原理,建立了控制半径计算方法,通过耦合气井井距和控制半径,建立了井间干扰程度评价模型。验证显示,模型计算结果与干扰试井测试结果一致,准确率高于动态分析法,证明了井间干扰程度评价模型的准确性。将模型应用于井网加密,以不产生井间干扰为原则,在满足经济极限井距的前提下,以储量控制程度最大为目标,对Y井区部署10口加密井,结果显示,动用含气面积新增3.74 km^(2),动用厚度新增60.59 m,储量动用程度提高7.41%。

Well pattern infill is an effective measure to improve the recovery factor of tight gas reservoirs,and the accurate evaluation of the interference degree among wells is the precondition of well pattern infill.The productivity equation,seepage mechanics equation and material balance principle of tight gas wells with fixed production are combined,and the calculation method of control radius is established.The sign function is used to connect the well spacing and control radius of gas wells,and the evaluation model of well interference degree is established.The verification shows that the model calculation results are consistent with the interference well testing results,and the accuracy rate is higher than that of dynamic analysis,which proves the accuracy of the model for evaluating the degree of interference among wells.The model is applied to well pattern infilling,with the principle of not generating inter-well interference,under the premise of meeting the economic limit well spacing,and aiming at maximizing the control degree of reserves,10 infilling wells are deployed in the Y well area.The results show that the gas bearing area is increased by 3.74 km^(2),the production thickness is increased by 60.59 m,and the reserve utilization degree is increased by 7.41%.