油气上窜速度的精确计算方法

上窜速度是反映油气活跃程度的一个非常重要的参数。对于钻井作业来说,直接影响钻井作业的井控安全。如果油气上窜速度不准确,很容易导致井涌、井喷等井控事故;同时也会造成钻井液密度的不合理,从而对油气层造成污染。现场用的迟到时间法计算油气上窜速度存在着较大的误差。根据油气在钻井液中运移的规律分析,得出油气上窜速度一种新计算方法,该方法综合考虑了钻具的排替作用、井身结构、以及开泵后油气在钻井液中的运移对其上窜高度的影响,对油气运移时间进行了修正,从而得到更加精确的油气上窜速度。经过现场实验表明,该计算方法可靠,可为准确判断油气活跃程度,为安全钻井作业提供依据。

Research on Accurate Calculation Method of Oil and Gas Upward Velocity

Oil and gas upward velocity is a very important parameter reflecting the activity of reservoir. During drilling,oil and gas upward velocity influences directly the safety of drilling operation. If not accurate,it is ease lead to accidents such as well kick, blowout and so forth, and cause the unreasonable drilling fluid density damaging the reservoir. The velocity obtained by using the method of lag time, which is widely applied during drilling, have higher error. In this paper, based on the analysis of the rule of oil and gas migration in the drilling fluid, a new calculation method was obtained. The method takes into account displacement effect of drilling tools, wellbore structure, BHA among other factors, and correctes the migration time of oil and gas. This method has been tested and the result shows that it has a high accuracy.