渤海变质岩潜山油藏储集层综合评价与裂缝表征

综合利用岩心、薄片和成像测井等资料,对渤海JZ25-1S油田变质岩潜山油藏进行了储集层评价和裂缝表征研究。将JZ25-1S潜山储集层纵向上划分为风化壳、半风化壳和基岩3段以及裂缝-孔隙型、孔隙-裂缝型和微裂缝-致密型3种储集层,并利用原油包裹体检测技术、区域地应力方向及声波全波列测井资料评价了裂缝的有效性。分析结果表明,研究区半风化壳储集层最为发育,孔隙-裂缝型储集层为主要产层,裂缝的主要走向与潜山主断层走向大致平行,以与现今最大地应力方向基本保持一致的晚期开启的倾斜裂缝最为有效。最后综合成像测井精细解释与生产实际应用,确定出定性-半定量的储集层划分标准,将潜山储集层划分为Ⅰ、Ⅱ、Ⅲ3个级别。图10表1参16

Reservoir evaluation and fracture characterization of the metamorphic buried hill reservoir in Bohai Bay

With core observation, thin slice identification and imaging logging data, reservoir evaluation and fracture characterization are studied in the Archaean metamorphic buried hill reservoir in the JZ25-1S field in Bohai Bay. The reservoir is divided into three zones vertically: weathered crust, semi-weathered crust and base rock, belonging to three reservoir types of fracture-pore pattern, pore-fracture pattern and micro fracture-compact pattern. The fracture effectiveness is estimated using crude oil inclusions testing technology, the direction of regional geostress, and full wave train acoustic logging data. It is concluded that the reservoir in the semi-weathered crust is most developed and the reservoir of pore-fracture pattern is the main oil producing layer. The main trend of fractures is nearly parallel to the main fault trend in the buried hill. The inclined fractures of late opening-mode parallel to the current direction of maximum geostress are the most effective fractures. At last, in combination of imaging logging interpretation with actual production, the qualitative and semiquantitative reservoir classification criteria are proposed and the buried hill reservoir is divided into three levels of I, II and III.