后效气测资料在控制钻井液密度值中的应用

Reasonable Controlling of Drilling Liquid Density Using Tripping Gas Data

针对钻井过程中泥浆密度需要及时调整的特点 ,提出了一套利用后效资料合理调配钻井液密度值的方法。首先分析确定了井筒内压力状态与气测数据间的关系 ,其次按照一定时间间隔选取相对应的气测数值与泥浆密度值 ,进而运用气测数值与钻井液密度值绘制出 1条曲线 ,并利用该曲线的变化区分出过平衡状态区、近平衡状态区和欠平衡状态区 ,其中近平衡状态区即为合理的钻井液密度值区间。该方法应用于青海柴达木盆地北缘的某口气、水显示异常活跃的预探井中 ,显示出应用简单灵活、方法实用、有利于钻井安全等优点 ,真正做到了“压而不死 ,活而不喷” 。

A method of adjusting and compounding drilling liquid density is put forward as need to adjusting liquid density in time during drilling well. First, it is analyzed and determined to the relationship between wellbore pressure state and gas logging data; Second, gas logging data and corresponding drilling liquid density values are chosen according to fixed time interval; Third, a curve is drawn for gas logging data and corresponding drilling liquid density values; Forth, overbalance , near balance and underbalance state area can be divided by using the curve change, and then the near balance state area just is reasonable drilling liquid density value area. The method was applied to a explorative well in Qaidam Basin of Qinghai Province ,the result shows that the method is practical, its application is simple and flexible, it is helpful for drilling safety. This method provides a new way to application of tripping gas logging dada.