龙女寺龙王庙组高含沥青储层开发潜力分析

Development potential of reservoirs with rich bitumen in Longwangmiao Formation,Longnvsi block,Sichuan Basin

四川盆地龙女寺区块下寒武统龙王庙组气藏与磨溪区块龙王庙组气藏毗邻,构造和沉积地质背景相似,但单井测试产量差异大,为了深入认识龙王庙组气藏的开发潜力,充分利用区内外静、动态资料,采用地质、测井、地震等联合攻关手段,分析了高产井主控因素,明确了高含沥青储层的开发潜力。研究结果表明:①>4%的储层为优质储层;②与磨溪区块相比,龙女寺区块储层厚度变薄,品质变差,但仍有优质储层发育;③储层普遍含沥青,但储量在优质储层发育的高含沥青区仍具有较强的可动用性;④气藏为构造背景下的岩性气藏,气井高产主要受优质储层控制,还与正向构造、裂缝发育正相关;⑤“内部亮点”仍是优质储层的响应特征。结论认为:位于构造高部位和裂缝叠合发育区的高含沥青储层仍具有较好的开发潜力。

Gas reservoirs of Longwangmiao Formation,Longnvsi block,Sichuan Basin,are adjacent to the counterpart in Moxi block.Both of them boast similar structural and sedimentary geological setting but their test yield is quite different in single well.So,some influential factors on high productivity were analyzed for Longwangmiao gas reservoirs by using geological,well-logging,seismic techniques based on static and dynamic data around the study area.Additionally,development potential was made clear for them with rich bitumen.Results indicate that(i)so called quality reservoirs must meet one requirement of porosity more than 4%;(ii)Long-wangmiao reservoirs in Longnvsi block character thinner thickness than that of Moxi block,resulting in their quality getting worse but a few quality ones still found;(iii)there broadly exists bitumen among these reservoirs,in which quality ones with rich bitumen have more reserves put to use;(iv)Longwangmiao gas reservoirs are lithological ones in the context of tectonic setting,and high-yield wells are mainly controlled by quality reservoirs and also related to positive structure and fractures;and(v)“internal highlight”re-mains response characteristics on quality reservoirs.It is concluded that highly bituminous reservoirs at a superimposition area of both structural high and fractures enjoy bright development potential.