Fault Systems and their Control of Deep Gas Accumulations in Xujiaweizi Area

A study of faults and their control of deep gas accumulations has been made on the basis of dividing fault systems in the Xujiaweizi area. The study indicates two sets of fault systems are developed vertically in the Xujiaweizi area, including a lower fault system and an upper fault system. Formed in the period of the Huoshiling Formation to Yingcheng Formation, the lower fault system consists of five fault systems including Xuxi strike-slip extensional fault system, NE-trending extensional fault system, near-EW-trending regulating fault system, Xuzhong strike-slip fault system and Xudong strike-slip fault system. Formed in the period of Qingshankou Formation to Yaojia Formation, the upper fault system was affected mainly by the boundary conditions of the lower fault system, and thus plenty of multi-directionally distributed dense fault zones were formed in the T2 reflection horizon. The Xuxi fault controlled the formation and distribution of Shahezi coal-measure source rocks, and Xuzhong and Xudong faults controlled the formation and distribution of volcanic reservoirs of Y1 Member and Y3 Member, respectively. In the forming period of the upper fault system, the Xuzhong fault was of successive strong activities and directly connected gas source rock reservoirs and volcanic reservoirs, so it is a strongly-charged direct gas source fault. The volcanic reservoir development zones of good physical properties that may be found near the Xuzhong fault are the favorable target zones for the next exploration of deep gas accumulations in Xujiaweizi area.     

南水北调中线水源地河水地球化学特征与流域侵蚀

丹江口水库及其上游流域是南水北调中线工程的水源地,本文讨论了水源地河流水化学与锶同位素(87Sr/86Sr)组成变化特征,目的在于了解水源地流域河流地表水溶质的物质来源以及岩石风化侵蚀过程和人为活动的影响。流域内河流水化学组成以Ca2+、HCO3-为主,Mg2+和SO42-次之,反映了碳酸盐岩风化溶解起控制作用的典型特征。水化学分析表明水源地河水受到工农业活动等人为因素的影响;河流87Sr/86Sr同位素地球化学研究表明,流域岩石风化输入至少存在三个不同端员(硅酸岩、石灰岩和白云岩)之间的混合。水源地流域内硅酸岩和碳酸岩的风化侵蚀速率分别为38.6和4.4 t/km2.a,总岩石风化侵蚀速率高于全球河流平均值。     

Geochemical characteristics and source analysis of inflow of mine water in Wang’ershan Gold Mine, Shandong

Through a systematic observation of water level and temperature, and a comprehensive analysis of the data on major/trace elements, nitrite, hydrogen-oxygen isotopes, the conclusion has been drawn that there are two relatively independent groundwater systems (cool water and hot water), and the geochemical indicators of hot/cool waters are described. The cool water system is relatively enriched in Ca2 , Mg2 and HCO3-. Its TDS is relatively low, about 1400–1800 mg/L. The hot water system is relatively enriched in K , Na , Cl- and SO42-. Its TDS is relatively high, about 2200–2300 mg/L. The cool water system is enriched in Ba, Ga, Cd, and the hot water system is enriched in B, Ti, Cr, Ni, Cu, Mo, Rb, and Cs, relatively. Especially, the contents of Rb and Cs in the hot water system are more than five times as high as those in the cool water system. The NO3- contents of cool water discharged from the gold mine are relatively high, and those of hot water are extremely low. The δD and δ18O values follow an increasing order of surface water>mine cool water>mine hot water. The cool water comes mainly from the lateral supply of phreatic water, while the hot water comes mainly from the vertical supply of deeply circulating structure-fracture water. The ratio of cool water over hot water was estimated to be about 1:1 by a water quality model..     

超压对川东南地区五峰组-龙马溪组页岩储层影响分析

四川盆地东南部保存条件较好的五峰组-龙马溪组页岩普遍存在超压,且在其他地质条件相同的情况下,超压页岩储层相对于常压、低压储层具有更高的孔隙度.研究表明,富有机质页岩在适中的热演化过程中,由于烃类的大量生成,形成较多有机质孔隙,增加了页岩储层储集空间;另一方面,烃类大量生成造成的超压对页岩储层储集空间保存具有至关重要的作用.川东南五峰组-龙马溪组优质页岩储层孔隙以有机质孔、黏土矿物孔等塑性孔为主,且缺少刚性矿物颗粒支撑,易被上覆地层有效应力压实.但超压的存在对于页岩储层具有保护作用,抵消了上覆地层有效应力对页岩储层的机械压实,从而使已形成的页岩孔隙保存下来,使页岩储集空间得以保留.研究超压对页岩储层孔隙度影响机制以及超压页岩储层发育模式对于四川盆地五峰组-龙马溪组页岩气勘探、开发具有重要意义.     

略论中国中、古生代石油资源远景

根据笔者在柴达木盆地侏罗系生油层和原生油藏的研究成果,指出我国应重视侏罗系油源的战略性侦察以及古生代及其以前海相油源战略性的研究。      

下扬子下寒武统岩相古地理及烃源岩条件研究

以下扬子下寒武统为研究对象,利用野外露头、岩心、岩石微观分析、有机地球化学等资料,在地层对比基础上,开展了下扬子下寒武统岩相古地理研究及烃源岩条件评价。结果表明：下扬子下寒武统主要发育硅质岩、硅质泥页岩、碳质泥页岩、灰质泥页岩、泥灰岩、白云岩6种岩石类型;地层可划分为3段,其中安吉-石台-上海地区三段发育齐全,其他地区一段大部分缺失,二段存在不同程度缺失;沉积相主要发育盆地、陆棚、斜坡、台地边缘、局限台地5种类型;烃源岩主要分布于石台-安吉、滁州-盐城、德兴-桐庐盆地相及周边陆棚相,石台-安吉地区是烃源岩发育最有利区,泥岩厚度300~700m,TOC为3%~9%,平均4.5%~5.76%;德兴-桐庐地区泥岩厚度200~400m,TOC为3%~9%,平均4.96%;滁州-盐城凹陷泥岩厚度50~200m,TOC为2%~4%。下扬子下寒武统烃源岩干酪根类型全部为Ⅰ型,有机质组分主要为腐泥组,以藻类体为主,含少量腐泥无定形体。下扬子下寒武统烃源岩均处于过成熟演化阶段,总体上由皖南盆地区向两侧台地逐渐降低,九江、景德镇、黄山及开化淳安地区受火山岩影响Ro在4.0%以上;安庆-溧阳-南通以南,湖州-苏州以西处于盆地、陆棚及斜披部位,埋深大,Ro为3.0%~4.0%;潜山、南陵、无为、金坛及苏北中新生代凹陷由于后期埋深较大,Ro在3.0%以上;其他区域Ro为2.0%~3.0%。     

准南霍玛吐背斜带天然气成因类型及来源

准噶尔盆地南缘霍玛吐背斜带经历了复杂的构造变动和演化,地质条件非常复杂,对油气成藏条件特别是油气成因一直存在争议。通过对目前已发现气藏的天然气组分、碳同位素、轻烃组成等特征分析,探讨了霍玛吐背斜带天然气成因类型及来源。组分分析结果表明,霍玛吐背斜带天然气为有机成因湿气,主要为腐殖型干酪根裂解气;碳同位素分析结果表明,霍玛吐背斜带天然气主要为煤型气,既有热解气,也有裂解气;轻烃分析结果表明,霍玛吐背斜带天然气为典型煤型气。综合成因类型分析结果认为,该区天然气主要来源于侏罗系烃源岩的煤系地层,既有热解气,也有裂解气。     

乌干达Albert地堑中新—上新统沉积特征及控制因素

乌干达Albert地堑位于东非裂谷西支北段,是晚中新世开始发育的陆内裂谷盆地。盆地油气资源丰富,中新—上新统砂岩是盆地的主要储层。综合运用录井、测井、岩心、孢藻和地震等资料分析认为,该时期气候温湿,湖平面振荡式上升;盆地物源体系复杂,发育Victoria Nile、Albert Nile和Kafu等多条主水系;盆地构造分带差异明显,由北至南依次发育缓坡带、中部断阶带、南部陡断带、断阶带和高角度斜坡带。北部缓坡带发育沿盆地长轴方向的正常三角洲;中部断阶带、南部陡断带及南部断阶带发育一系列垂直于盆地轴向的扇三角洲及湖底扇;高角度斜坡带发育沿盆地长轴方向的扇三角洲及近岸水下扇。沉积体系的类型及展布特征与物源体系、构造分带、湖平面升降和气候特征密切相关。综合分析认为盆地北部区域、东部边界断层下降盘及盆地南部是良好的储盖组合发育区。     

中国近海盆地油气地质特征及勘探开发进展

通过半个多世纪的海洋油气勘探实践与科技创新,中国近海盆地油气勘探开发取得了长足进展和里程碑式的突破。2010年,中国海洋油气年产量突破5 000×104 t油当量大关,实现了建成“海上大庆”的目标。2011年以来,中国近海油气勘探开发进入了高速发展阶段,海域油气产量增长迅猛,目前,渤海盆地原油年产量已超过3 000×104 t且油气产能还在递增。系统阐明了中国近海含油气盆地构造结构类型、沉积充填特征、油气成因类型及烃源供给关系、油气成藏组合类型及运聚成藏模式等基本油气地质特点,概括分析了中国近海主要盆地油气（水合物）勘探开发进展,以期为挖掘已获得重大发现的盆地的剩余资源以及有效指导新盆地油气的高效勘探开发提供借鉴。     

海南岛北部海湾重金属污染分布及来源

伴随社会经济的发展,海南岛附近海域出现不同程度的重金属污染。2019年我们采集了位于海南岛北部的铺前湾、澄迈湾、后水湾、洋浦湾的表层沉积物,对照国家海洋沉积物质量标准（GB18668—2002）,使用地累积指数、重金属污染指数、重金属污染程度指数以及潜在生态风险指数等多种参数评价了各海湾重金属分布及污染状况。结果显示,砷（As）是各海湾中污染最明显的重金属元素。澄迈湾及铺前湾总体污染状况较为严重,洋浦湾总体污染状况较轻。船舶燃油燃烧、水产养殖、化肥施用、矿业废水等人类活动都会带来不同程度的重金属污染,需采取适当措施,有针对性地对海南岛北部海湾重金属污染进行防治。