The Silurian hydrocarbon exploration in the northwest Tarim Basin had long been fruitless, till Well XSD1 drilled in 2018 in the Shajingzi structural belt, northwest Tarim Basin tapped industrial gas flow from the Silurian for the first time. The reservoir-forming model and resource extent need to be made clear urgently. Based on the comprehensive research of drilling, formation testing, geochemical data, and sedimentary and accumulation history, in combination with field surveys, experiments, structure interpretation and reconstruction of structure evolution, it is found that: (1) The northwest Tarim Basin had widespread tidal deltaic deposits in the Silurian period, which contain good reservoir-cap combinations; (2) the Shajingzi fault and associated faults connected the Cambrian—Ordovician source rocks in the Awati sag, and controlled the formation of Silurian structural traps, hence, the traps turned up along the structural belt in an orderly pattern and came together into contiguous tracts; (3) the Silurian petroleum in Shajingzi structural belt was dominated by gas, and the major accumulation period was the Himalayan period when the traps fixed in shape; (4) the Silurian gas resources in the Shajingzi belt were estimated at around 2.018×1011 m3 and Silurian gas resources of the northwest Tarim Basin were estimated at 2.03×1012 m3 implying huge exploration potential, so this area will become a major area for reserve and production increase from clastic strata in the basin; (5) with the Shajingzi fault of large scale and long active time connecting deep source rock layers, multiple formations in Lower Paleozoic of Shajingzi structural belt may have breakthroughs in hydrocarbon exploration.
地热能具有清洁、低碳、环保、稳定的特点,干热岩作为地热能的一种,是一类新兴的环境友好型资源,能够有效推进构建能源结构利用的多元化.通过对研究区太古界干热岩地热储层综合评价技术的研究,参照岩性特征及储层发育特征,建立了利用多种测井信息进行岩性识别、储层划分和地层温度评价的方法;在岩心和岩屑录井资料分析的基础上,利用不同岩性测井曲线特征差异性分析和交会图进行岩性的识别和划分;结合常规测井、成像测井和偶极阵列声波测井等多种测井信息,形成干热岩地热储层的识别方法,并建立储层类别划分标准;利用时间推移测量井温的方式进行地层温度的推算.实际应用已证明这一测井评价方法的适用性与有效性,可为干热岩的有效开发提供技术支撑.
青城子矿集区位于华北板块北缘,辽东裂谷带中段,矿集区内产有众多大型、中型铅锌矿床、金矿床、银矿床.为深入了解矿集区内铅锌矿床、金矿床、银矿床空间分布的差异性及成矿热液的运移方向,在收集整理前人研究成果的基础上,总结了矿床的时空分布规律.结果表明:铅锌矿床的成矿年龄集中于 225～221 Ma,金矿床和银矿床的成矿年龄集中于238～197 Ma;空间上,以印支期双顶沟岩体为中心依次向外产出铅锌矿床、银矿床、金矿床;成矿流体的运移方向以甸南—榛子沟一带为中心,分别向东西两侧及沿断裂迁移.结合矿集区的成矿规律与野外地质调查,初步建立了青城子矿集区找矿预测地质模型.研究可为推动在青城子矿集区内开展进一步找矿工作提供新思路.
四川省牦牛坪矿床是全球第三大稀土矿床(仅次于我国白云鄂博和美国芒廷帕斯),近期在其外围取得了找矿新突破——在龙家沟一带第四系(厚达50m以上)之下探获了隐伏的两类厚大稀土矿体,第一类为氟碳铈矿-霓辉石-莹石-重晶石型,第二类为氟碳铈矿-萤石-重晶石-方解石型.其中,氟碳铈矿-萤石-重晶石-方解石型矿脉整体厚度(视厚度)超过100 m,稀土平均品位4.6%.经多晶X射线衍射分析,此类矿石主要由方解石(40%～75%)、萤石(25%～58%)、重晶石(5%～25%)和氟碳铈矿(1%～16%)组成.根据矿石的结构、构造及矿物组成,可将其形成分为早、晚两个阶段:早阶段矿石主要呈中粗粒结构,块状构造、斑杂状构造;晚阶段矿石呈中细粒角砾状构造、流动构造.此类品位高、易采选的新型矿体的发现,是新一轮找矿突破战略行动实施以来在稀土矿产勘查方面取得的重要突破.建议在牦牛坪矿床及其外围进一步开展寻找氟碳铈矿-萤石-重晶石-方解石脉型稀土矿体的地质找矿工作.
宜洛煤田高山南部勘查区属华北地台渑临台坳区,断层构造较发育.为了厘清高山南部勘查区的构造特征及其对煤层的影响,通过对区内二维地震、钻探资料以及野外地质资料的综合分析,探讨了勘查区构造特征及构造演化规律,认为区内构造变形主要包括印支期、燕山期和喜马拉雅期3 个阶段,断层构造主要有印支期近EW向断层、燕山晚期NW向推覆构造及喜马拉雅期NE向张性断层,对勘查区内煤层均有较大破坏,在勘查区东部二1 煤层中存在"二层楼"现象.研究可为宜洛煤田下一步寻找煤炭资源提供新的思路和找矿靶区.
