钻井中钻柱浮力分析与计算

ANALYSIS AND CALCULATION OF DRILLING STRING BUOYANCY IN PETROLEUM DRILLING

杨进 张留计 王俊生

石油大学, 北京昌平 102200 中原石油勘探局钻井四公司, 河南濮阳 457000

浸泡在钻井液中的钻柱,会受到钻井液浮力的影响。在钻井施工过程中,井眼轨迹预测和控制及钻柱摩阻计算都应考虑浮力的影响。在钻井过程中,浮力的计算一般忽略了钻杆的内外加厚影响,而对于复合钻柱的浮力计算有不同的观点。文中对直井和斜井两种情况下的钻柱浮力进行了详细分析,提出了钻柱浮力的计算新方法,并在现场进行了验证。

Buoyancy effect occurs when the drilling string is submerged in drilling fluid, and it is of great importance for drilling practice. It impacts the well trajectory control and causes influence on friction during pipe tripped. It should also be considered in many other field operations. This paper presents a new method for buoyancy calculation, based on detail mechanical analysis of pipe in vertical and inclined well. This method combines the calculations of drill collar, drill pipe and composite drilling string, and it takes the internal and external addition parts of drill pipe into consideration, which is usually ignored in conventional calculations.It is further testified and proved beneficial for field drilling.

10.3969/j.issn.1000-7393.2000.03.004