提高辽河外围盆地气测解释符合率的探索与实践

The exploration and practice for increasing the gas logging interpretation coincidence rate in Liaohe external basin

辽河油田外围盆地储集层原油性质大部分属于中质油或重质油,反映在气测组分上,稠油气测组分表现为以C1为主,C1相对含量大于90%,其余为C2和C3,C4很少或没有,加之其储集层具有低孔、低渗和低压的特点,使气测显示幅度偏低,单凭外围盆地组分数据很难区分油层和气层,辽河坳陷气测解释图板已经不能直接应用。为了提高气测解释符合率,针对外围盆地气测录井显示特征,研究了气测录井的显示规律,通过消除组分基值对气测解释的影响,修正了辽河坳陷气测解释图板,重新确定外围盆地的3H解释标准。由41口井380层实例验证,气测解释符合率由原来的80.6%提高到88.2%。

The oil nature of the reservoirs in the external basin of Liaohe Oilfield mostly belongs to the medium oil or heavy oil,the components on the gas logging are mainly performed as C1,the relative content of C1 is more than 90%,the rest are C2 and C3,C4 is little or no.In addition,its reservoir properties are low porosity,low permeability and low pressure,its gas logging shows are lower,it is difficult to distinguish oil zone from gas only by the component data of the external basin,and the gas logging interpretation chart for Liaohe Sag can not be directly applied.To increase the interpretation coincidence rate of gas logging and in accordance with the display features of gas logging in the external basin,the author studied the gas logging rules,and put forward the concept of component background value,and re-determined 3H interpretation standards for the external basin by eliminating the impact of the base value of the components on the gas logging interpretation and correcting the gas logging interpretation chart of Liaohe Sag.The instances of 380 zones from 41 wells verified that the gas logging interpretation coincidence rate was increased to 88.2% from 80.8%.