惠州油田火成岩潜山裂缝特征及主控因素OACSTPCD

To clarify the reservoir quality and development potential of the igneous buried hill reservoir in Huizhou Oilfield,the characteristics,spatial distribution,and key controlling factors of fractures were studied comprehensively by using the data of core,imaging logging,and thin section.Results show that three groups of NW-,NE-,and EW-trending fracture systems are developed in the buried hill reservoirs,of which the NW-trend-ing fracture system is dominant.The main frequency of the fracture dip angle is 49°～60°.Three types of frac-tures were distinguished,i.e.,structural fractures,dissolution fractures,and diagenetic fractures.The structural fractures are major types,followed by dissolution fractures,and diagenetic fractures are isolated and contributing little to the reservoir properties.The development of fracture was controlled by tectonic,lithologic,and fault and fluid action.Multi-stage tectonic movement was the mechanical basis of the fracture formation in the buried hill rock.Granite and diorite were conducive to the formation of fractures.The trap-control fault affected the fracture development in range of about 150 m,and the influence range of the secondary faults was about 80 m.Based on quantitative characterization of main controlling factors of fracture development,the dominant region of fractures in the buried hill was predicted by PR multiple information probability fusion method.In addition,four dominant fracture zones were recognized in the weathering zone in the buried-hill.This research provided an important ref-erence for reservoir evaluation and development of the buried hill reservoir in Huizhou oilfield.