精细控压多级并联节流管汇系统研究

Research on Multi-Level Parallel Choke Manifold System

现代精细控压钻井中,由于节流阀的压力调节特性与节流阀开度之间存在较强的非线性关系,现有的节流管汇很难通过单个节流阀实现全开度范围内的精确调节。为了能使普通节流阀满足回压控制精度的要求,提出了利用并联节流管汇实现回压精细控制的思路,并对并联管路的流动特性进行了研究,模拟了四支路并联节流管汇精确控制井口回压的工作过程,分析了并联节流管汇的压力调节特性。与传统节流管汇相比,并联节流管汇具有压力调节特性曲线线性度良好、调节区间大、调节精度高、对节流阀精度要求低、使用寿命长等优点,能获得显著的经济效益,具有较大的工程应用价值,为进一步研究精细控压钻井及其地面控制系统提供了一定的技术参考。

Modern precise managed pressure drilling technology proposes higher requirements on control accuracy of wellhead back pressure,but because of intense nonlinear relationship between pressure regulation characteristic and opening presented on throttle valve,it is difficult to achieve accurate regulation through single throttle valve within the scope of full opening for the current choke manifold.In the purpose of meeting the requirements of control accuracy of back pressure with traditional throttle valves,based on the research of flowing characteristic of parallel pipelines,this paper put forwards a thinking of realizing fine back pressure control by means of parallel choke manifold,and the pressure regulation characteristic of parallel choke manifold was analyzed by simulating the working process of parallel choke manifold with four branches that accurately control wellhead back pressure.Compared with the traditional choke manifold,parallel choke manifold has good linearity of characteristic curve on pressure regulation,larger regulation range,higher regulation accuracy,lower accuracy demand and longer service life of throttle valves and other obvious advantages,which have significant engineering meaning and economic benefit.This provides some technical references for further study on fine managed pressure drilling and ground control system.