井下圆球运动分析与新型试压体设计

Analysis of ball movement and design of newpressure test body in downhole

摘要:

在油、气、水井井下作业中，圆球广泛地应用于管柱试压、坐封和分段(层)压裂等施工作业。为准确计算现场施工时圆球到达设计点时间（即候球时间），通过对圆球运动过程和受力分析得出新的候球时间计算公式，并指出圆球绕流阻力系数、圆球直径、圆球密度和压井液性能等是影响候球时间的关键因素，为优化施工设计提供了依据；同时提出了一种能减少候球和反洗球时间的新型管柱试压体设计构思，为进一步优化施工作业奠定了基础。

关键词:井下作业;圆球;候球时间;新型管柱试压体

Abstract:

In the downhole operation of oil, gas and water wells, the ball is widely used for pipe pressure testing, sealing and multi-stage (layer) fracturing. In order to accurately calculate the time when the ball arrives at the design point (i. e., the waiting time), the new formula of the waiting time calculation is developed by analyzing the movement process and the forces of the ball. It is pointed out the key factors affecting the waiting time include the coefficient of resistance around the ball, the ball diameter and density, and fracturing fluid properties, which provides a basis for optimizing the construction design. At the same time, a new type of tubular pressure test body that can reduce the waiting time and backwashing time is proposed, laying the foundation for further construction optimization.

Key words:downhole operations; ball; waiting time; new pressure test body