四川盆地卧龙河储卤构造地下卤水的水化学特征及成因

四川盆地东部卧龙河储卤构造在深埋地下2000m左右的碳酸盐岩中赋存海相同生沉积卤水。该储卤构造的深部断裂、背斜西翼陡断带断层及破碎带构成了卤水的主要储集空间。卤水的矿化度为105.67~129.4g/L,为Cl-Na型水。将该深层卤水各水化学组分含量与对应的黄海水蒸发浓缩曲线对比,得知其富集Br-、I-、Sr2+、B2O3等微量元素或成分,K+不富集。卤水δD、δ18O资料显示其起源于古海水。利用离子系数及化学组分的分析结果,表明地下卤水在高温高压、封闭的还原环境中,发生了脱硫酸作用和白云岩化作用等化学成分演化作用。     

沉积盆地深层地下卤水资源量评价之若干探讨

沉积盆地深层地下卤水(包括富钾卤水)处于深埋封闭和无补给状态; 卤水具有很高的测压水头, 天然条件下处于停滞状态, 不同储卤构造之间无水力联系; 具有多个平行叠置的储卤层, 不同储卤层之间无水力联系; 储卤层空隙性和渗透性差, 卤水主要富集于背斜、裂隙带和断层裂隙带; 卤水水化学和物理特性在短期内比较稳定; 卤水储存资源量较大, 在开采条件下卤水资源逐渐减少趋于衰竭。本文在分析总结沉积盆地深层地下卤水资源量评价的现状和卤水特征的基础上, 讨论和阐明深层地下卤水资源评价中的若干问题, 包括深层卤水资源量的类型和评价方法的选取、储卤层计算范围和边界的概化处理、渗透性分区和卤水密度影响的处理、测压水头的换算、钻井预测水头降深的确定等, 目的在于提高深层地下卤水资源量评价计算的精度。     

非稳定井流解析法评价深层地下富钾卤水可采资源量

在沉积盆地内有时只有一个钻井揭露深层储卤层地下卤水。如果能合理地进行水文地质条件的概化并了解储卤层的有关水文地质参数,可以利用非稳定井流解析法通过求得钻井卤水水头降低至储卤层顶板所需的时间来估算钻井的卤水可采资源量。据此求得四川盆地油罐顶储卤构造油1井和罗家坪储卤构造川25井的富钾地下卤水可采量分别约为7.495×106 m3和8.951×106m3,作为初步的卤水资源量数据。     

柴达木盆地昆特依盐湖含杂卤石地层高分辨率矿物学研究

柴达木盆地昆特依盐湖杂卤石资源丰富,是开展现代内陆盐湖杂卤石成因机制研究的良好载体.精细刻画沉积特征对阐释沉积矿床成因具有重要作用.本研究以昆特依盐湖大盐滩矿区ZK3608钻孔岩芯14.08-25.48 m段碎屑-杂卤石沉积韵律为研究对象,开展高分辨率矿物学研究,结合石盐流体包裹体化学组成和石盐中微量元素分析,尝试从高分辨率沉积学和矿物学的角度探讨杂卤石的成因.研究结果显示,石盐层产出的杂卤石含量低但分布范围广,为原生矿物;碎屑层中的杂卤石主要为次生矿物.石盐层与碎屑层之间存在一个过渡层位,该层位的杂卤石高度富集且矿物组成复杂,推测是由于原生与准同生杂卤石短时间内先后形成导致的.结合石盐流体包裹体化学组成所代表的古卤水变化特征分析表明,Ca-Cl型深部油田卤水的补给对研究区不同时期杂卤石的形成有重要影响.地球化学特征综合分析指示,石盐层的原生杂卤石由富钾镁的浓缩卤水与Ca-Cl型深部油田卤水混合直接生成;而过渡层位的杂卤石受到气候变化与Ca-Cl型深部油田卤水补给的共同作用.     

试用有限单元法评价深层地下卤水资源量

用有限单元法评价浅层地下水资源量,是人们十分熟悉的。但对深层地下卤水资源量的评价,尚无完善的方法。本文对某储卤构造深层储卤层进行概化,用有限单元法模拟卤水生产过程并作出预报,提供了相应的结果。     

环境温度对盐湖卤水化学组成及储卤层渗透性变化的制约

柴达木盆地昆特依盐湖浅部储卤层是一个多场耦合的动态平衡系统,受到水动力、气候、化学等多种因素控制。本文对昆特依盐湖浅部储卤层不同季节(夏季和冬季)卤水组成和储卤层渗透性特征进行了分析研究。结果表明:卤水中的主要离子含量从夏季到冬季发生了明显的变化,其中,K、Mg、Ca、Cl的含量都相应增加,增加幅度为:Cl、Mg、K、Ca;而SO_4~(2-)和Na的含量却均有下降,且SO_4~(2-)下降更显著;抽水试验计算结果发现,从夏季到冬季,钻孔ZK08渗透系数K由178m/d降至97m/d。本文研究表明,随着环境温度的降低,芒硝(Na_2SO_4)从卤水中结晶析出,是以上现象发生的主要原因,随着芒硝的析出,促进了含K、Mg、Ca等硫酸盐矿物(杂卤石)的溶解,使得卤水中K、Mg、Ca浓度增加;另一方面,析出的芒硝一定程度上堵塞了储卤层的孔隙,卤水的粘度也因温度降低而增加,这两个因素共同作用降低了储卤层渗透性。     

论四川盆地地下卤水资源开发利用的现状及对策

四川盆地地下卤水资源储量大,卤水浓度较高,并含有I、Br、K、Li等多种有用组分。地下卤水多沿构造隆起部位富集,并具有天然气和卤水同层的特点。指出目前对地下卤水开发利用发展不均的现状,以及多以制盐为主,开发利用单一等现象。提出深化对地下卤水资源量的评价,加强对地下卤水综合利用的研究,组成跨行业的开发实体等建议。     

四川盆地东北部某储卤构造深层卤水资源量容积法评价的改进模型研究

深层地下卤水资源量的评价具有较大难度,一方面由于深部地质及水文地质参数难以准确获取,另一方面地下卤水资源量评价方法尚无规范可循。传统的深层卤水区域资源量评价方法一般采用容积法,但容积法对储卤层空间形态描述较简单,同时也无法处理深层卤水各参数严重不均一的问题,容易引起误差的累积。提出了容积法的一种改进模型,首先利用Opengl API三维渲染技术来建立储卤层三维模型,再利用克里格法对储卤层三维模型进行网格化,建立模拟单元,用模拟的方法来解决各参数的不均一性,进而求取资源量。该方法继承了资源量评价中"圈区算量"的基本思想,可以获得更准确的计算结果。为了便于该方法的应用,进行了软件实现,并以四川盆地东北部某储卤构造为例对该构造资源量进行了试算。结果表明该方法能更充分地利用深部地质参数,是对容积法的一种有效改进。     

“四川盆地深层地下卤水资源量评价及其方法的研究”成果

该课题是地矿部“七五”重点科技攻关项目“我国钾盐成矿条件及找矿方向研究”中的三级课题(86008-04-03),由中国地质大学(北京)水文地质及工程地质系承担,1987年8月～1990年6月历时近3年,现已全面完成了任务。该研究成果已于1990年7月 6日经专家评议通过验收。 此成果从四川盆地深层卤水资源特点和开发利用的实际出发,经过充分调查研究并在分析前人资料的基础上,全面论述了四川盆地深层卤水的富集特征、卤水资源的独特属性,总结了不同类型储卤构造和不同性质储卤层卤水的储集特点,从理论上提出了深层卤水资源量的分类和评价原则,继而总结了多种先进方法,并利用这些方法对四川盆地区域卤水资源量以及12个重点储卤构造各类卤水资源量进行具体计算,提供了可供利用的定量结果。取得了以下主要成果。     

腾格里地区盐湖的盐类沉积特征

腾格里沙漠122个盐湖分为石盐、石盐-芒硝、石盐-白钠镁矾及芒硝(石膏)4种类型。盐湖含盐系厚度一般4～9m,总体呈现下部为含盐碎屑沉积,上部以盐类沉积为主,构成储卤层,卤水赋存其中,由湖岸至湖心储卤层厚度增长。含卤层理渐小,卤水含KCl渐高。盐湖中矿物主要为碳酸盐矿物,以芒硝、石膏为主的硫酸盐矿物、石盐以及粘土矿物。盐湖卤水以晶间卤水为主。许多卤水含K+大于2g/L。K+含量最高的红盐池,平均含量达19.14g/L。对钾矿而言,在盐湖分布相对集中地区,有一定的综合开发利用前景。     

Evolution of isotopic composition and deuterium excess of brines in the Sichuan Basin, China

The isotopic composition and parameters for deuterium excess of brines, which were sampled in the Si-chuan Basin, show obvious regularities of distribution. The brine isotopic composition shows distinct two systems of marine and terrestrial deposits, with the Middle Triassic strata as the boundary. Brine hydrogen isotopic composition of marine deposits is lower while oxygen isotopic composition is higher than that of the SMOW, respectively, indicating that the brines were derived from seawater with different evaporating degrees at different times. From the Sinian strata, up to the Cambrian, Permian Maokou Formation and the Triassic Jialingjiang Formation, the δD values of brines tend to become relatively positive with the strata becoming younger. Brines of terrestrial deposits are considered to have been derived from precipitation and their isotopic composition is close to the globe meteoric water line (GMWL). Brines of transitional deposits between marine and terrestrial ones (the Upper Triassic Xujiahe Formation) have δD and δ18O values falling between the two end members of marine deposit brines and precipitation, indicating that the brines are a mixture of precipitation and vaporing seawater. Water samples from the brine-bearing strata of different ages show various deuterium excesses (d) with an evident decreasing trend as the age of strata gets older and older. Brine-bearing strata of the Triassic Leikoupo-Jialingjiang Formation, the Permian Maokou Formation, the Cambrian and Sinian strata are all carbonate rocks which have experienced intensive water/rock reaction and the deuterium excess essentially changes with time. All brine-bearing-strata surrounding the basin or faults, as well as those brine wells exploited for resources, have been obviously influenced by the precipitation supply. Therefore, the deuterium excesses of their brines have increased to different extents, depending on the amount of involvement of meteoric water. The variation and distribution of d values of the brines from different Triassic strata are related to the embedded depth of the strata. The deuterium excesses of brines become lower with increasing burial depth of the strata.     

咸化湖盆沉积物有序分布及其控制因素——以渤南洼陷沙四上亚段为例

咸化湖盆存在碎屑岩、化学岩及混积岩共生的沉积现象,但多类型沉积物有序分布的机制尚不明确。本文以渤南洼陷沙四上亚段为例,开展了咸化湖盆多类型沉积物有序分布及控制因素的分析,结果表明：渤南洼陷沙四上亚段低位域沉积期以碎屑岩沉积为主,湖侵域和高位域则出现化学岩与混积岩,由近岸到远岸呈扇体、砂岩滩坝、混积岩滩坝、碳酸盐岩滩坝、盐湖、半深湖及深湖有序分布;化学岩主要受水体环境控制,水体古盐度大于10‰是化学岩形成的基础,盐度和深度共同控制碳酸盐岩、膏岩以及盐岩分布,同时水体深度对不同成因类型的碳酸盐岩及碎屑岩分布也产生影响;碎屑岩主要受物源地貌控制,物源区位置及物源供应强度决定着碎屑岩的沉积位置和规模大小,同时古碳酸盐岩的发育影响着现今碳酸盐岩的发育位置;古地貌位置的高低及坡度的陡缓决定着砂体成因类型,同时古地貌还影响着生物礁生长及碳酸盐沉淀;咸化湖盆多类型沉积物有序分布受古水深、古盐度、古物源、古地貌的共同作用。     

地下含水层水资源赋存条件及其水化学特征—以贵州省安龙县幅为例

以贵州省安龙县1∶50 000水文地质图幅为例,采用含水层探采井的水质、水量监测数据,分析不同含水层水资源赋存特征及其与水化学的相关性。研究结果表明:（1）研究区含水层可分为纯碳酸盐岩管道含水层、非纯碳酸盐岩裂隙含水层、碎屑岩裂隙含水层、松散岩类孔隙含水层4种类型,各含水层中地下水水化学类型均以HCO-Ca?Mg型为主;（2）除非纯碳酸盐岩含水层探采井的降深与水体中Mg2+、HCO-3浓度呈现出显著的负相关性（R2=-0.77/-0.74）外,其余离子浓度与钻井单位涌水量、降深的相关性均不显著,相关系数(R2)均小于0.3;（3）非纯碳酸盐岩含水层和松散岩类含水层的总矿化度（TDS）、总硬度（TH）含量均比纯碳酸盐岩含水层低5 mg?L-1以上,TDS、TH的高值区均集中于纯碳酸盐岩含水层中,而低值区则分布于松散岩类含水层。      

Origin of brines in the Upper Silesian Coal Basin (Poland) inferred from stable isotope and chemical data

Brines in the Miocene formations of the Upper Silesian Coal Basin have isotopic composition close to SMOW, which identifies them as the connate marine water. However, controversies exist on the origin of brines in the Carboniferous formations. Isotopic and hydrochemical data exclude any relationship to marine water and enrichment by evaporation. The most common brine which occurs at great depths can be identified as the oldest infiltration in a very hot climate (δ¹⁸O ⋟ −2‰, δD ⋟ −20‰, Cl⁻ content 34 to 140 g/L). This brine is free of SO₄²⁻ and U, and rich in Ba²⁺ and²²⁶Ra. Its salinity is probably related to the leaching of evaporites and intensive weathering of rocks during the Rotliegendes.Other brines are difficult to identify because their isotopic contents are within the range of mixing between the oldest brine and the Quaternary waters (δ¹⁸O ⋟ 10‰, δD ⋟ 70‰). Isotopic and hydrochemical data allow identification of several occurrences of brine formed by meteoric water of a warm Tertiary climate, after the last marine transgression in the Tortonian. That brine is rich in SO₄²⁻ and contains moderate contents of²²⁶Ra and U. Its salinity is thought to result from leaching of Miocene evaporites. Two other identified types of brines can be related to some infiltration periods before the last marine transgression. The sources in salinity of these 2 types remain unknown. Mining activity results in a common occurrence of mixed brines. When the Quaternary component dominates, its identification is easy from the isotopic composition, whereas the end brine component can ususally be identified by chosen ion ratios and the presence or lack of sulphates.     

松辽盆地白垩系泉头组碎屑沉积岩岩石地球化学特征及其地质意义

松辽盆地庆安地区白垩系泉头组碎屑沉积岩主要由砂岩、泥岩和粉砂岩类组成。通过对白垩系泉头组碎屑沉积岩岩石样品的岩石化学分析表明 :主元素化学分类结果主要为长石砂岩、页岩 ,少量岩屑砂岩和硬砂岩 ;稀土元素分布模式显示其明显富集轻稀土及Eu负异常 ,并与NASC和PAAS稀土分布模式相似 ;碎屑沉积岩与上地壳的微量元素含量比值曲线显示为平坦型 ,这说明沉积岩是在活动性较弱的构造背景下缓慢沉积 ,具有被动大陆边缘和活动大陆边缘沉积物的特点。松辽盆地庆安地区白垩系泉头组碎屑沉积岩物质来源于张广才岭海西期花岗岩 ,后者的物源来自于上地壳。     

The“Sand-Mud” Sedimentary Record and Its Diagenetic System in Shore-shallow Lacustrine—A Case Study of Eocene Kongdian Formation in Jiyang Depression

The sand-mud sedimentary record develops widely in the shore-shallow lacustrine, which can be a good oil and gas reservoir cap combination. It has important significance in petroleum geology. This paper takes the Kongdian Fm. of Eocene in Jiyang Depression as an example to study the formation mechanism and diagenetic system of the sand-mud sedimentary record in the shore-shallow lacustrine. The study indicated that sandstone-mudstone sedimentary strata at macroscopic level includes sand-mud duality, mudstone vein and sandstone lens in the Kongdian Fm. of Jiyang Depression, and there are some transitional clastic rocks at the microscopic level (Clastic particles, clay and carbonate cements are included in the transitional clastic rocks). The sandstone-mudstone sedimentary strata mainly formed in the material transformation of the shallow-water deltas and conjugate shock in the shore-shallow lacustrine. The thickness is mainly restricted by material source and water dynamic condition, and the sand-mud transitional clastic rocks are restricted by the dynamic mechanism and sedimentary differentiation of the lake water. The sandstone-mudstone sedimentary strata is composed of a closed diagenetic system. Early compaction-drainage and differential compaction, middle and late clay mineral transformation, structural water and organic acid emissions during the diagenetic process of mudstone influence the diagenesis of sandstone. The closed diagenetic system of sand-mud transitional clastic rocks is mainly related to the structural maturity of clastic rocks.     

江汉盆地潜江凹陷古近系潜江组含盐岩系沉积特征与沉积环境

潜江组盐层间的层段（盐间段）由砂岩和非砂岩两部分组成。其中非砂岩分布广泛，主要由单层厚度为毫米-厘米级累积厚度达几十厘米至几米的含盐韵律组成，并多为复成分的蒸发盐矿物、碳酸盐矿物及陆源的粘土和细碎屑矿物组成的混积岩。过去，人们对盐间段非砂岩的研究主要基于对岩性的认识，对于其沉积特征和沉积环境方面的研究较薄弱。本文通过对潜江凹陷西北部王场构造3口井共约151米岩芯的精细研究，对盐间段沉积特征和沉积环境进行了系统分析。认为潜江组盐间段湖盆环境为常年性较深水分层盐湖，大体可分为微咸水湖、半咸水湖、咸水湖和盐湖，水体深度自下而上逐渐变浅。     

Fluid-rock interactions in a geothermal Rotliegend/Permo-Carboniferous reservoir (North German Basin)

Comprehensive data on the chemical composition of reservoir rocks and geothermal brines from the geothermal well doublet Groβ Schönebeck (North German Basin) drilled into a Rotliegend sedimentary and Permo-Carboniferous volcanic rock reservoir were sampled over the past years. They were characterized with respect to their major and minor elemental composition including various isotope ratios. The study considered the impact of drilling and reservoir operations on fluid composition and aimed at determining fluid–rock interactions to gain information on fluid origin and hydraulic pathways.The highly saline fluids (up to 265 g/L TDS) show δ ¹⁸O and δD of water (2.7–5.6 and −3.1–15, respectively) as well as δ ³⁴S of sulfate (3.6–5), and ⁸⁷Sr/⁸⁶Sr ratios (0.715–0.716) that resemble Rotliegend brines from an area located around 200 km in the west (the Altmark). Halogen ratios indicated that brines developed predominantly by evaporation of meteoric water (primary brine) together with halite dissolution brine (secondary brine). Indication for mixing with Zechstein brine or with younger meteoric water was not found.No geochemical distinction was possible between fluids deriving from different rock formations (dacites or sedimentary rocks, respectively). This is due to the evolution of the sediments from the effusive rocks resulting in a similar mineralogical and chemical composition and due to a hydraulic connectivity between the two types of rock. This connection existed probably already before reservoir stimulation as indicated by a set of faults identified in the area that could connect the Rotliegend formation with both, the volcanic rocks and the lower units of the Zechstein. Additional geochemical indication for a hydraulic connectivity is given by (1) the very high heavy metal contents (mainly Cu and Pb) in fluids and scaling that derive from the volcanic rocks and were that were also found in increased amounts up at the Zechstein border (Kupferschiefer formation). (2) The ⁸⁷Sr/⁸⁶Sr isotope ratios of fluid samples correspond to the ratios determined for the sedimentary rocks indicating that initially the fluids developed in the sedimentary rocks and circulated later, when faults structures were created by tectonic events into the volcanic rocks.     

The tempo-spatial characteristics and forming mechanism of Lithium-rich brines in China

With the technological development of exploitation and separation, the primary sources of lithium have gradually changed from ore to brine, which has become the main raw material, accounting for more than 80% of the total production. Resources of lithium-bearing brine are abundant in China. This paper has summarized the spatial and temporal distribution, characteristics, and formation mechanism of the lithium-rich brine in China, aiming to provide a comprehensive set of guidelines for future lithium exploitation from brines. Lithium-rich brines usually exist in modern saline lakes and deep underground sedimentary rocks as subsurface brines. The metallogenic epoch of China’s lithium-rich brine spans from the Triassic to the Quaternary, and these brines exhibit obvious regional distribution characteristics. Modern lithium-rich saline lakes are predominately located in the Qinghai-Tibet Plateau. In comparison, the subsurface lithium-rich brines are mainly distributed in the sedimentary basins of Sichuan, Hubei, Jiangxi provinces and so on in south Block of China, and some are in the western part of the Qaidam Basin in Qinghai province in northwestern China. Lithium-rich saline lakes are belonging to chloride-enriched, sulfate-enriched, and carbonate-enriched, while the deep lithium-rich brines are mainly chloride-enriched in classification. On the whole, the value of Mg/Li in deep brine is generally lower than that of brine in saline lakes. The genesis of lithium-rich brines in China is not uniform, generally there are two processes, which are respectively suitable for salt lakes and deep brine.