Lithium Extraction from Carbonate-type Saline Lake by Utilizing of Geothermal Solar Pond in Tibet

正1 Introduction The geothermal solar pond is a kind of special solar pond.It is different from traditional solar pond,which high temperature geothermal water can be used to heat brine.When the salt in the brine reaches saturation temperature,it precipitate out and is separated from the brine.Compared with solar pond,the geothermal solar pond does not rely entirely on solar radiation as a heat     

RMS提取技术在溶洞型碳酸盐岩储层地质建模中的应用

三维地质建模在油气田的开发过程中发挥着越来越重要的作用。在碎屑岩储层的应用中已经形成一套较为成熟、效果良好的方法技术,但是在碳酸盐岩储层预测的应用中尚处于探索阶段。应用PETREL储层建模软件,以地震属性RMS提取技术为建模核心方法,建立塔河4区碳酸盐岩溶洞的分布模型,并且对塔河4区实际洞穴与此模型预测结果进行对比统计,72个样点中吻合的有54个,吻合率为75%,较为准确的再现塔河4区地下空间分布,此模型可为以后的勘探开发提供有效依据。     

埋藏历史对碳酸盐溶解-沉淀的影响——以四川盆地东北部三叠系飞仙关组和塔里木盆地北部奥陶系为例

埋藏成岩过程中碳酸盐的溶解与沉淀强烈控制着深埋藏地层中碳酸盐岩储层质量,与之有关的地质过程是人们多年来不懈研究的热点领域。热流体沿断裂向上运移所造成的碳酸盐溶解成为近年人们普遍认可的模式,但这不能圆满解释大量存在的不与断裂伴生的深埋藏碳酸盐的溶解机制。基于四川盆地东北部和塔里木盆地北部深埋藏碳酸盐溶解与沉淀机制的研究,认为埋藏过程中盆地的沉降与抬升是碳酸盐溶解与沉淀以及次生孔隙发育的另一重要机制,在改变流体对碳酸盐饱和状况方面具有和热流体沿断裂向上运移相同的重要性。研究表明:与川东北飞仙关组类似的埋藏历史更有利于深埋藏成岩过程中碳酸盐的溶解,主要特点是当前埋藏深度不是最大埋藏深度,在最大埋藏深度附近发生热化学硫酸盐还原作用,其后盆地持续抬升造成温度降低和碳酸盐溶解,与之有关的次生孔隙形成所造成的岩石力学性质的变化与上覆载荷减小可以得到平衡,次生孔隙得以保存,岩石储层质量改善;塔里木盆地北部的奥陶系埋藏历史不利于深埋藏成岩过程碳酸盐的溶解,主要特点是当前埋藏深度是最大埋藏深度,古喀斯特发生之后盆地持续沉降造成温度升高和碳酸盐沉淀,并与上覆载荷的增加同步发生,结果是孔隙的封堵、岩石的致密化和储层质量的变差。     

松潘地区白龙江隆起泥盆纪至三叠纪碳酸盐碎屑流沉积及其古地理意义

白龙江隆起地区可见泥盆纪至中三叠世的碳酸盐碎屑流, 其中泥盆纪至早三叠世的碳酸盐碎屑流沉积主要见于白龙江隆起北翼, 中三叠世的碳酸盐碎屑流则见于白龙江隆起南北两翼和西缘。这些碳酸盐碎屑流沉积有两种类型: 一种为仅含深水砾屑的碎屑流沉积, 另一种为深水和浅水砾屑兼有的碎屑流沉积。通过对这些碎屑流沉积进行详细的野外和室内研究, 分析其沉积特征, 认为这些碳酸盐碎屑流形成于碳酸盐台地斜坡环境。结合前人的研究成果分析认为, 白龙江地区北侧自泥盆纪开始, 存在一个大致东西走向, 向北倾斜的碳酸盐斜坡, 斜坡向南则为松潘－甘孜地块的主体部分, 从侧面佐证了松潘－甘孜地块的存在。至三叠纪安尼晚期, 由于松潘地块主体部分沉陷, 形成自东向西延伸的白龙江半岛, 中三叠世白龙江隆起周缘碳酸盐碎屑流沉积的环状分布则指示出白龙江半岛的空间展布特征。     

振幅属性在川中地区大安寨段中的应用——以J区块为例

川中地区大安寨段地层为典型的碳酸盐岩,主要储层为大-亚段。模型正演结果表明地层厚度与地震振幅强度存在一定关系。当地震波经过油气层时,其高频成分能量衰减较不合油气层时严重;谱分解技术利用最大熵谱方法,将地震数据变换到频率域,其地震振幅强度表征了油气分布情况。振幅属性在J区块大安寨段的应用效果明显,既可以定性预测大-亚段厚度,也能预测油气分布情况。     

塔中I号坡折带上奥陶统台缘礁滩复合体建造模式

塔中Ⅰ号坡折带的台缘高能区发育上奥陶统良里塔格组礁滩体,主要包括生物礁丘、灰泥丘、粒屑滩、滩间海等沉积类型,纵向上表现为粒屑滩、灰泥丘、礁丘的多旋回组合。单个礁滩复合体下部发育粒屑滩,上部为灰泥丘和(或)礁丘,之上为下一旋回的粒屑滩亚相所覆盖。横穿宽3～10km的区域,特别是台地边缘向陡坡转折的高地为礁生长相对集中区,而向内侧则更多出现滩相。不同沉积期礁滩单元分布范围不同,从良三段到良一段沉积期间内呈现逐步向塔中Ⅰ号坡折带迁移的缩减趋势。经后期多次成岩作用和构造破裂的改造,形成沿台缘分布且具有非均质性变化的礁滩型储层。     

Latitudinally different responses of Tethyan shoal‐water carbonate systems to the Early Aptian oceanic anoxic event (OAE 1a)

Ocean‐wide anoxic events represent intensively investigated anomalies in the global carbon cycle. Most previous research has focussed on hemipelagic and pelagic settings and on the relationship between black‐shale deposition and carbon‐isotope excursions. The study of ocean‐wide anoxic events and coeval shallow‐water settings is now increasingly seen as an interesting complementary approach, but one that is not without problems. Whereas platform drowning characterizes the Early Aptian of the northern Tethyan margin, Lithocodium–Bacinella‐rich facies and ongoing shoal‐water sedimentation at the southern Tethyan margin (Oman) bears important information on potential causes of carbon‐cycle perturbations. The present paper seeks to test the supra‐regional relevance of the Oman data by investigating coeval central Tethyan limestones. Three Lower Aptian shoal‐water sections in Istria (Croatia), deposited on the isolated Adriatic Carbonate Platform, are investigated applying chemostratigraphy (carbon and strontium) and detailed sedimentological analysis. The focus is on peritidal to lagoonal facies characterized by mass occurrences of Lithocodium–Bacinella, an enigmatic microencruster community. Lithocodium–Bacinella facies occurs predominantly in layers ranging from one to several centimetres in stratigraphic thickness, with several layers merging to metre‐thick packages. Growth fabrics within the layers include oncoidal morphotypes, lumps, interconnected patches and columns, layers and rare nodular to massive bindstone facies. These growth patterns show a remarkable regional extent and consistency over study sites distributed several kilometres apart. This widespread distribution suggests that specific Lithocodium–Bacinella morphotypes might serve as regional stratigraphic markers. The high‐resolution carbon‐isotope chemostratigraphy presented here is based on pristine rudist shells and matrix micrite samples and calibrated against strontium‐isotope data obtained from screened rudist low‐Mg calcite. The chemostratigraphic data are consistent with existing biostratigraphic data and place the studied strata at the onset of Early Aptian oceanic anoxic event 1a. Moreover, results indicate the near‐coeval nature of Lithocodium–Bacinella bloom facies in Istria and Oman. The outcomes of this study point to latitudinally different responses of Tethyan shoal‐water carbonate systems (platform drowning versus Lithocodium–Bacinella blooms) to the ocean‐wide anoxic event 1a.     

Increased terrigenous influx but no drowning: palaeoenvironmental evolution of the Tunisian carbonate platform margin during the Late Aptian

During the Aptian, some carbonate platforms of the sub‐tropical realm (for example, on the northern Tethys margin or in the Gulf of Mexico) were affected repeatedly by severe perturbations in the carbonate production factory and drowning, preferentially during global warming events such as the Early Aptian Oceanic Anoxic Event 1a and a prominent mid‐Late Aptian warming interval. These platform growth crises have been explained mainly by strongly increased coastal runoff (for example, siliciclastics and nutrients) in combination with pronounced eustatic sea‐level rises. In the last few years, increasing evidence suggests that carbonate platforms of lower latitudes were generally less or even not affected by environmental perturbations during these events. This raises the question as to the responsible factors that promoted platform growth or decline in different latitudinal areas. In this study, Upper Aptian (Middle Gargasian to Uppermost Clansayesian) inner‐tropical carbonate ramp deposits of the Serdj Formation at Djebel Serdj, north‐central Tunisia are studied in detail with regard to microfacies, lithology, biostratigraphy and chemostratigraphy. These data allow reconstruction of the palaeoenvironmental evolution of the Tunisian carbonate platform margin and investigation of its response to the prominent mid‐Late Aptian warming interval. The unusually expanded, 600 m thick Serdj Formation consists of limestones, marlstones and siltstones, suggesting deposition within mid‐ramp to inner‐ramp palaeoenvironments. Deposits of the mid‐Late Aptian are represented by quartz‐rich platform carbonates and siltstones, probably resulting from increased coastal runoff on the Tunisian shelf as a response to global warming and accelerated water cycling. The siliciclastic input was accompanied by elevated nutrient levels as indicated by a partial decline in the abundance of oligotrophic biota and mass occurrences of orbitolines and green algae. Carbonate platform drowning during the mid‐Late Aptian, as reported from the sub‐tropical realm, has not been identified. A comparison with other tropical river‐influenced platforms suggests that none of them drowned during the mid‐Late Aptian. One important reason might be widespread arid to semi‐arid climatic conditions within lower latitudes during that time, promoting platform growth due to comparably low nutrient runoff.     

碳酸盐岩中锶元素地球化学特征及其指示意义

应用锶指示古环境的方法很多,其中以锶的含量和与Sr配对的相应的元素比值作为指示剂,具有典型代表性。本文以北京下古生界碳酸盐岩为研究对象,采用ICP-MS分析技术测试了49件样品中Sr、Ba、Cu的含量。以锶的含量、Sr/Ba、Sr/Cu比值作为地化指标,深入探讨了锶的地球化学特征。系统的分析了Sr含量,Sr/Ba、Sr/Cu比值对不同的沉积环境的地质响应。指出从浅海环境到深海环境Sr含量及其相应的元素比值增加趋势明显,对沉积环境具有重要的指示作用。并且,Sr的分布还受到不同沉积旋回的影响,研究沉积作用对Sr分布的影响时,应在同一沉积旋回中进行。此外还深入研究了不同岩性、不同沉积旋回中Sr的分布特征,探讨了影响Sr分布的不同因素。归纳了锶对沉积环境的指示作用。就成岩作用对碳酸盐岩中锶分布的影响,结合前人的工作,进行了探索性的分析。     

四川东部华蓥山三叠系海相碳酸盐岩对海水信息的保存性评估

海相碳酸盐成岩蚀变及其对海水信息保存程度的认识与评估在古海洋学和沉积地质学等学科领域研究中有着重要意义,尤其对于沉积地球化学和化学地层学等方面的研究是必不可少的基础工作。笔者通过对四川东部华蓥山仰天窝剖面三叠系海相碳酸盐岩样品的微观组构观察、阴极发光和微量元素等分析表明,大多数的样品保留了较好的原始沉积组构,具有极弱和弱的阴极发光强度、较低的Mn含量和较高的Sr含量,同时也具有较小的Mn/Sr值。只有6个样品被认为遭受了较大的成岩蚀变而对海水信息的保存程度较差,需要被剔除,而大多数的样品只遭受了较小的成岩蚀变作用,较好地保留了当时海水的信息,仍然在很大程度上代表了当时的海水。