Kekeya Condensate Field In 'the West Section Of The Reservoir Characteristics And Quantitative Evaluation

Kekeya Condensate Gas Field has been mined for more than30years and now enters into late-mid-exploitation period. Since the remaining prtroleum resource is not too much, it is difficult to maintain stable product. In order to exploit the gas field efficiently, reservoir characteristics and quantitative comprehensive evaluation of the lower part of the5th section of Xihefu foramation(X52), which is the major reservoir of the gas field, are studied in this paper.Fine and silty sandstone are the main reservoir rocks of X52formation, which has a brownish red color. Based on the observation of thin sections and casting thin sections, the reservoir space is found to have three types:primary pores, secondary pores and microcracks. The secondary pores are the mian type and the primary pores are rare. All this shows that the Xihefu formation has been through strong diagenetic transformation stage. Compared with other reservoir of the gas field, X52formation has better porosity, permeability and less heterogeneity. Of several types of heterogeneity, areal heterogeneity is obvious. The continuity of sand body is better in north-south direction than in east-west direction. Such a character is consistent with source direction. Both sand distribution and heterogeneity confroms with the microfacies, whih shows that the storage capability is strongly affected by deposition.Gray Correlation Method and Principal Factor Analysis combined with Cluster Analysis Method are used in this paper for reservoir quantitative evaluation of X52formation. With the purpose of comparing the evaluation results of this two methods, same assessment parameters are selected, including porosity, permeability, sandstone percent, thickness and shale content. Compared with traditional methods, the two methods seem more reasonable. Comparing the two evaluation results with well test results, Gray Correlation Method is found to be more accurate. It is showed that reservoir callssification can be more precise by using Gray Correlation Method in this area.