摘要
页岩油是与页岩气并存的非常规连续型油藏。北美A-29区块Tuscaloosa Marine Shale(TMS)层发育页岩油,但其资源潜力不清,现今转入开发的钻井极少。TMS层岩性组合为夹心饼式,上、下为致密层,中间为页岩储层,认清其页岩油资源状况及有利区分布范围,为下一步勘探开发提供指导显得尤为重要。运用体积法计算出A-29区块页岩油原始地质储量丰度为(7.36～63.22)×104m3/km2,页岩油原始地质储量为(0.30～2.56)×108m3。通过"五度"(埋藏深度、厚度、有机质丰度、有机质成熟度及脆性度)特征分析,认为A-29区块TMS层具有较好的页岩油勘探潜力,且具有较好的可压裂性,区块东南部为页岩油下一步勘探的有利区。TMS层下部发育的致密砂岩和致密灰岩含有大量的自由水,如果水平井压裂措施不当,易压穿下部致密层而导致透水,存在完井风险。
Shale oil play is continuous petroleum accumulations just like shale gas, both of them are unconventional resources. The A-29 block locates in north of favorable prospecting area of Tuscaloosa Marine Shale(TMS), which is one of the best shale oil potential areas in North America. Because of being lack of geologic awareness, the resources potential is not clear, the next step of exploration is hard to deepen. Now, knowing the resources potential and selecting favorable area are very important for next exploration and development. Analyses of lithologic association of TMS formation indicate that upper layer and lower layer are tight rock, and middle rock is shale oil reservoir. OOIP is calculated by volumetric method and the range is from 0.30×108 m3 to 2.56×108 m3, and resources abundance is from 7.36×104 m3/km2 to 63.22×104 m3/km2. Based on research of some key geologic parameters which are depth, thickness, TOC, Ro and brittleness, the results show that A-29 block is a good shale oil exploration area, TMS formation is so hard for hydraulic fracturing, and the shale oil favorable area is in southeast of block. But the exploration risk is in existence, the lower layer of TMS is tight sand and tight limestone which contains free water. Once the process of fracture stimulation is not proper and length of fracture is not controlled, the breakthrough will happen. So, high risk of completion should be noticed.
出处
《岩性油气藏》
CSCD
2013年第3期66-70,91,共6页
Lithologic Reservoirs
关键词
页岩油
资源潜力
风险分析
TMS层
墨西哥湾盆地
shale oil
resource potential
risk analysis
Tuscaloosa Marine Shale formation
Gulf of Mexico
