水平井探测半径计算方法

Calculation method of investigation radius of horizontal wells

根据质量守恒原理,将水平井转化为虚拟直井,然后通过状态方程将各个参数和压力联系起来,从而对水平井探测半径的计算方法进行研究。研究结果表明:①新推导出的探测半径计算公式在形式上表现为关于时间的非线性隐函数。②油井探测半径随时间的增长而增大,储层特性参数对探测半径与时间的典型曲线具有显著影响。③多区复合油藏水平井探测半径的曲线明显表现出复合油藏的多区特性。④N区复合油藏的典型曲线上出现N-1个拐点,拐点代表压力波对相邻2个区带界面的响应,内区半径的增大会使相应的拐点向右上角移动。

The principle of mass conservation was used to convert a horizontal well into a virtual vertical well,each parameter and pressure were connected through the state equation,and then the calculation method of inves‐tigation radius of horizontal wells was studied.The results show that:(1)The newly derived formula for the in‐vestigation radius is a nonlinear implicit function with respect to time.(2)The investigation radii of oil wells in‐crease with time,and the reservoir characteristic parameters have obvious influence on the typical curve of inves‐tigation radii and time.(3)The typical curve of investigation radii of horizontal wells in multizone composite reser-voir obviously shows the multizone characteristics of composite reservoir.(4)There are N-1 inflection points on the typical curve of composite reservoir in N zone,which represents the response of pressure wave to the inter‐face of two adjacent zones.The increase of inner zone radius will make the corresponding inflection points move to the upper right corner.