准噶尔盆地金龙油田二叠系佳木河组火山岩岩相组合及产能差异

Lithofacies assemblages and differential productivity of volcanic rocks in the Jiamuhe Formation， Jinlong oilfield， Junggar Basin

鲍李银 庞雄奇 崔新璇 陈宏飞 高军 邹亮 赵振丞 王琛茜 王雷 李闻东 刘利

Liyin BAO Xiongqi PANG Xinxuan CUI Hongfei CHEN Jun GAO Liang ZOU Zhencheng ZHAO Chenxi WANG Lei WANG Wendong LI Li LIU

为解决准噶尔盆地金龙油田二叠系佳木河组火山岩岩相类型及优势储层展布特征不清、油气资源开发难度较大问题。基于岩心观察、测井分析及实验化验数据，系统分析了研究区火山岩的岩相类型、储层物性与储集空间特征，建立了岩相组合模型，提出了对产能的控制因素。研究结果表明：①准噶尔盆地金龙油田火山岩具有爆发相、溢流相和火山沉积相三大类。爆发相以熔结火山碎屑岩和安山质火山角砾岩为主，平均孔隙度大于10 %，为主要储层；溢流相以熔岩为主，平均孔隙度小于6 %，火山沉积相物性差。②研究区火山岩储层以气孔、杏仁体内孔及溶蚀孔为主，原生粒间孔较少，爆发相与溢流相顶部溶蚀孔洞发育最为显著。裂缝主要为构造缝和溶蚀缝，发育程度与到断裂距离紧密相关，中-酸性溢流相以斜交缝、网状缝为主，基性溢流相以高角度直劈缝为主。③研究区有中-酸性热碎屑流亚相与中-酸性溢流相互层、基性热碎屑流亚相与基性溢流亚相频繁互层、中性空落亚相与中性溢流亚相互层、中性空落亚相与中-酸性热碎屑流亚相互层等4种岩相组合。产能最高的为中性空落亚相与中-酸性热碎屑流亚相互层组合，其次为中-酸性热碎屑流亚相与中-酸性溢流相互层组合、中性空落亚相与中性溢流亚相互层组合，基性热碎屑流亚相与基性溢流亚相频繁互层组合组合日产量最低。④储层有效厚度与含油饱和度对产能的影响最大，其次为孔隙度和地层压力。

Volcanic rocks in the Permian Jiamuhe Formation of the Jinlong oilfield in the Junggar Basin exhibit unclear lithofacies types and dominant reservoir distribution， which hinder the exploitation of the oil and gas resources therein. To address these challenges， we systematically analyze the volcanic facies types， reservoir physical properties， and storage space characteristics in the study area using data from core observations， log analysis， and laboratory tests. Accordingly， we establish lithofacies assemblage models， while clarifying their controlling effects on productivity. The results indicate that the volcanic rocks in the Jinlong oilfield in the Junggar Basin can be categorized into three facies： explosive， overflow， and volcanic sedimentary facies. The explosive facies， among others， consists primarily of welded volcaniclastic rocks and andesitic volcanic breccias， and exhibits an average porosity exceeding 10 %， forming dominant reservoirs. While the overflow facies is dominated by lavas， featuring an average porosity of below 6 %， and the volcanic sedimentary facies exhibits poor physical properties. In the volcanic reservoirs in the study area， vesicles， intra-amygdale pores， and dissolution pores predominate， with a minor presence of primary intergranular pores. Additionally， dissolution vugs are most developed at the top of the explosive and overflow facies. Fractures in the volcanic reservoirs are dominated by structural and dissolution fractures， with developmental degrees closely related to their distance from faults. The intermediate-acidic overflow facies mainly exhibits oblique and reticulate fractures， while the mafic overflow facies is dominated by high-angle， straight-split fractures. The study area exhibits four lithofacies assemblages： interbedded intermediate-acidic pyroclastic flow subfacies and intermediate-acidic overflow subfacies， frequently interbedded mafic pyroclastic flow subfacies and mafic overflow subfacies， interbedded neutral air-fall subfacies and neutral overflow subfacies， and interbedded neutral air-fall subfacies and intermediate-acidic pyroclastic flow subfacies. The interbedded neutral air-fall subfacies and intermediate-acidic pyroclastic flow subfacies exhibits the highest productivity， followed by interbedded intermediate-acidic pyroclastic flow subfacies and intermediate-acidic overflow subfacies and interbedded neutral air-fall subfacies and neutral overflow subfacies， and with the frequently interbedded mafic pyroclastic flow subfacies and mafic overflow subfacies coming at last in daily production. The productivity of the volcanic reservoirs is governed most significantly by the effective reservoir thickness and oil saturation， followed by porosity and formation pressure.

10.11743/ogg20250110