利用地化参数预测稠油油藏开采难度

生物降解原油的粘度与生物降解程度相关,而原油中生物标志物的分布则随生物降解程度的不同而有差异.原油粘度与原油中饱和烃含量呈负相关,与极性化合物浓度呈正相关;与w(Pr+Ph)/w(nC₁₇+nC₁₈)值呈正相关,与w(Pr+Ph)/w(C₃₀藿烷)值呈负相关.原油粘度与w(Pr+Ph)/w(胡萝卜烷)值关系也很密切.利用相应地化参数可预测原油粘度,并进而初步预测原油开采难度.对辽河油田冷43块S₃²段6个油组的预测结果表明,原油粘度随埋深增加而升高,在油水界面附近达到最高值.该油藏的开采难度具有与之相似的特征.

Prediction of difficulty for developing heavy oil reservoir with geochemical parameters

The viscosity of biodegraded oil is highly correlated to biodegradation degree. The distribution of some biomarkers in oil varies with the different biodegradation degrees.Oil viscosity in negatively correlated to saturated hydrocarbon concentration in oil and w(P_r+Ph)-to-w(C₃₀hopane)ratio,and it is also positively correlated to polar compounds’concentration and w(P_r+Ph)-to-w(nC₁₇+nC₁₈) ratio.In addition,oil viscosity has close correlation withw(P_r+Ph)-to-w(carotene) ratio.Those geochemical parameters can be used to predict oil viscosity and thus to preliminarily evaluate oil production ifficulty.The predicted resuls from six sand bodies of second member of Sha-3 in Leng-43 block of Liaohe Oilfield show that the viscosity of oil increase with well depth and reaches the highest value near oil-water contact.The distribution of production difficulty in this reservoir is similar to the distribution of oil viscosity.