梨树断陷沙河子组地层水特征与成藏关系

地层水是与油气共存的地下水,它受沉积环境、流体流动等多种因素影响,与油气的生成、运移、聚集和成藏有着重要联系。对梨树断陷东南斜坡带沙河子组地层水总矿化度、变质系数、脱硫系数、碳酸盐平衡系数等化学特性参数的分析表明,参数低值区与已知油气藏分布吻合,东南斜坡带沙河子组地层水封闭条件较好,有利于油气聚集和保存,十屋9、河山4等区域具有勘探潜力。     

伊通盆地岔路河断陷地层水化学特征与油气保存关系

对伊通盆地岔路河断陷古近系地层水的矿化度、水型及变质系数、脱硫系数的研究表明,该区地层水总体为NaHCO3型水;总矿化度偏低;平面上,孤店斜坡的油气保存条件最差,梁家构造带最好,垂向上,具明显的垂向分带性,万昌组保存条件最差;变质程度高.对地层水化学特征平面及剖面展布的分析,不仅为测井解释提供了准确的参数,更重要的是结合其他地质因素能够指出油气保存的有利地区.     

新疆甜水海地区红山湖泉水化学特征及其意义

通过开展甜水海地区红山湖的泉水与湖水水文地球化学相关测试分析,探索区内水化学成分形成过程以及水体地球化学特征与来源,从而获得与油气有关的水文地球化学信息。结果显示：红山湖泉水总体呈弱碱性,以微咸水为主,水体主要离子质量浓度随着矿化度增加而增加,水化学类型为Na-HCO₃型;其主要补给为大气降水,且补给的大气降水在顺断裂或裂隙深循环过程中与围岩发生了水岩作用;矿化度、水化学类型以及泉水特征系数指示其代表的地下水体水动力较弱,且变质程度较深,与油田中油气伴生的地层水特征相似,推断该区地质环境整体利于油气形成与保存。     

辽河盆地西部凹陷欢-双地区下第三系油田水体系及地球化学场

油田水体系的地球化学场中蕴含着丰富的石油地质学含意,其研究对指导油气勘探和开发有重要的意义。辽河盆地西部凹陷欢-双地区下第三系油田水可划分为六个体系,即:(1)沙四段油田水体系,(2)沙三段下部油田水体系,(3)沙三段中-上部油田水体系,(4)沙二段油田水体系,(5)沙一段油田水体系和(6)东营组油田水体系。虽然这六个体系的油田水均为低矿化度的重碳酸钠型水,但其矿化度和还原系数场不尽相同;这些不同不仅表现在油田水体系之间的地球化学场异常区面积有差异,而且地球化学场异常区位置也有变化。一般认为油田水体系中矿化度场的正异常区和还原系数场的负异常区为有利的油气聚集区和保存区。     

南海北部沉积盆地油田水水化学特征及其成因分析

油田水是沉积盆地中的重要流体,研究其水文地球化学特征对油气生成、富集等有重要指示意义。为进一步研究南海珠江口盆地珠三拗陷和北部湾盆地涠西南凹陷油田水的特征和成因,分别在珠三坳陷的珠江组和珠海组采集油田水样5个,在涠西南凹陷的涠洲组采集油田水样4个,对研究区油田水进行了常规阴阳离子含量、D和18O同位素组成分析。结果显示:珠江口和北部湾盆地油田水溶解性总固体总体较高,均为Cl—Na型水,油田水各特征离子间关系(钠氯系数、氯镁系数、钙镁系数)和氢氧同位素关系共同显示两处油田水均起源于海水并储存于封闭性较好的地层中,在埋藏过程中可能还经历了较小程度的蒸发和降水补给,并推测其形成受薄膜渗滤作用影响。     

塔河油田奥陶系油田水特征离子及意义

塔河油田奥陶系油田水的可溶物质主要成分与海水一致,表明其主要为海相成因.油田水中不同的离子组成、浓度及离子参数指示特定的地质意义:塔河7号区块与其他区块处于不同的水文系统;塔河油田奥陶系碳酸盐岩层中存在着大量的粘土矿物和胶结物,造成溶液具有相对高钙和低钠现象;钠氯系数、碳酸盐平衡系数、脱硫系数等在井间分布具有一定的规律性,总体上从南东向北西方向变化,反映了油气从满加尔坳陷向塔北地区运移的趋势.     

四川盆地西部三叠系—侏罗系地层水化学特征与油气保存关系

对四川盆地西部40余口钻井的三叠系—侏罗系地层水化学特征的分析表明:地层水的变质程度在纵向上随着地层埋深而增大;区域上从盆地边缘龙门山区向盆地坳陷中心,矿化度逐渐变高,水型由开启环境的Na HCO3型过渡到封闭环境的Ca Cl2型。海相中三叠统雷口坡组的水动力环境以多样性为特征,但整体保存条件良好;陆相侏罗系上部,地层水的水动力交替较强,保存条件偏差,中下部整体进入区域性的"保存区";陆相上三叠统须家河组总体保存条件良好,大多数位于"保存区"。地层水化学性质与油气保存的关系分析表明,油气保存的"有利区"主要位于川西坳陷带,"较有利区"位于龙门山前锋推覆带,"不利区"位于龙门山前山推覆带。     

马海盆地深部孔隙卤水矿床水化学特征及成因

通过数理统计、聚类以及离子特征系数等分析方法,对柴达木马海盆地的深部砂砾石层孔隙卤水水化学特征进行了分析。卤水离子浓度空间分布特征表现为pH、Cl^-、TDS和Na+浓度值变化范围较小,分布均匀,而K^+、Rb^+以及Br^-、Mg^2+、Li^+、Sr^2+、I^-、B2O3、Ca^2+、Cs^+、NO3^-、SO4^2-等离子浓度分布不均匀,差异显著;Cl^-、TDS、Na^+、K^+、Mg^2+和Li^+与SO4^2-聚为一个亚类,表明卤水演化过程中有酸性液体的参与;K^+含量自西向东有增大的趋势,与Mg^2+和Li^+的变化具有相关性;离子特征系数反映出蒸发残余及盐岩溶解的多源性特征。研究区水化学类型为单一的氯化钠型,这种单一的物源可能与推测的更新统下伏盐岩层有关。     

山东东营凹陷前古近系水化学场、水动力场与油气成藏

东营凹陷前古近系水化学特征对沉积环境有着良好的响应,从太古宙到早古生代的寒武纪,由于海水的侵入,使矿化度和氯离子含量出现增大的物质响应,但从奥陶纪到中生代,构造作用变强,水深总体变浅,保存环境变差,矿化度和氯离子含量总体降低。水化学剖面具有一定的分带性,大致可以划分为3种水文环境:水文流畅带(0~1.1km)、水文阻滞过渡带(1.1~1.75 km)和水文迟缓带(>1.75 km)。在各带矿化度、主要离子含量及离子组合系数等水化学参数具有不同的响应,其中水文阻滞过渡带和水文迟缓带对油气成藏有利。主要发育CaC l2型水和NaHCO3型水,随着矿化度的升高,NaHCO3型水逐渐被CaC l2型水取代。前古近系水动力场具有一定的对称性,从太古宙到中生代,水动力场中心和水动力场对称轴线发生变化。盆地内部发育以离心流为主的水动力场,在盆地边缘发育以向心流为主的水动力场,在离心流与向心流相接触的离心流泄水地带是油气聚集成藏的有利位置。     

淮北平原东部孔隙潜水水质参数因子分析探讨

利用因子分析方法,对淮北平原东部的蚌埠市、亳州市、阜阳市、淮北市和宿州市浅层潜水水质为研究对象,对其实测的11个环境要素——K^＋、Na^＋、Ca^2＋、Mg^2＋、HCO3^-、SO4^2-、Cl^-、NO3^-（以N计）、总硬度、溶解性总固体、游离二氧化碳进行因子分析。结果表明,该地区实测的11个环境要素可提取3个主因子,第一主因子包括NO3^-（以N计）、Ca^2＋、Cl^-、Mg^2＋、K^＋、SO4^2-,共6个环境要素,主要反应了与水的硬度相关的几个参数以及Ca^2＋、Mg^2＋和K^＋的主要存在形式;第二主成份包括Na^＋和SO4^2-,反应了该地区钠盐的主要存在形式;第三主成份包括游离二氧化碳和HCO3^-两个要素。     

Origin and migration of brines from Paleozoic strata in Central Tarim,China: constraints from 87Sr/86Sr, δD, δ18O and water chemistry

Chemistry of major and minor elements, ⁸⁷Sr/⁸⁶Sr, δD, and δ¹⁸O of oilfield waters, and ⁸⁷Sr/⁸⁶Sr of whole rock were measured from Paleozoic strata in the Central Tarim basin, NW China. The aim is to elucidate the origin and migration of formation water and its relation to petroleum migration. High salinity oilfield waters in Carboniferous, Silurian and Ordovician reservoirs have maintained the same Na/Cl ratio as seawater, indicative of subaerially evaporated seawater. Two possible sources of evaporitic water are Carboniferous (C_II) and Cambrian, both of which contain evaporitic sediments. Geographic and stratigraphic trends in water chemistry suggest that most of the high salinity water is from the Cambrian. Strontium, H and O isotopes as well as ion chemistry indicate at least 3 end member waters in the basin. High-salinity Cambrian evaporitic water was expelled upward into Ordovician, Silurian and Carboniferous reservoirs along faults and fractures during compaction and burial. Meteoric water has likely invaded the section throughout its history as uplift created subaerial unconformities. Meteoric water certainly infiltrated Silurian and older strata during development of the C_III unconformity and again in recent times. Modern meteoric water enters Carboniferous strata from the west and flows eastward, mixing with the high salinity Cambrian water and to a lesser degree with paleometeoric water. The third end member is highly radiogenic, shale-derived water which has migrated eastward from the Awati Depression to the west. Enrichment of Ca and Sr and depletion of K, Mg, and SO₄ relative to the seawater evaporation trajectory suggest waters were affected by albitization of feldspars, dolomitization, illitization of smectite, and SO₄ reduction. The mixing of meteoric water occurred subsequently to seawater evaporation, main water-rock interactions, and brine migration. The direction of brine migration is consistent with that of petroleum migration, suggesting water and petroleum have followed the same migration pathways.     

Petroleum pollution and evolution of water quality in the Malian River Basin of the Longdong Loess Plateau,Northwestern China

The possible sources of water pollution and the evolution of water quality in the Malian River Basin of China’s Longdong Loess Plateau were studied based on chemical analysis. Concentrations of major chemicals in the river were related to the distance downstream from the source of the river and the surface water in the upstream had good quality, while the river from Southern Huanxian County to Qingcheng County was seriously polluted. Groundwater quality was generally good in the phreatic aquifer beneath the loess plateau, with bicarbonate and calcium dominant, but salinity was high and petroleum pollution was present in many parts of the study area. Both surface water and groundwater quality have declined rapidly during the past 20 years, leading to much of the water unsafe to drink and unsuitable for use in irrigation. The substances released into the water included industrial wastes, domestic sewage, organic and inorganic fertilizers, and pesticides, as well as a range of other substances that are harmful to humans. However, petroleum contamination caused by the oil industry in the Longdong oilfield is the largest source of pollution that infiltrates surface water and groundwater, leading to deterioration of water quality. It is recommended that oilfield management must be improved and the petroleum products and wastes must be disposed carefully to reduce the risk of further spills and pollution.     

Mass transfer of H2O between petroleum and water: Implications for oilfield water sample quality

Water mass transfer can occur between water and petroleum during changes in pressure and temperature. This process can result in the dilution or concentration of dissolved ions in the water phase of oilfield petroleum–water samples. In this study, PVT simulations were undertaken for 4 petroleum–water systems covering a range of reservoir conditions (80–185 °C; 300–1000 bar) and a range of water-petroleum mixtures (volume ratios of 1:1000–300:1000) to quantify the extent of H₂O mass transfer as a result of pressure and temperature changes. Conditions were selected to be relevant to different types of oilfield water sample (i.e. surface, downhole and core samples). The main variables determining the extent of dilution and concentration were found to be: (a) reservoir pressure and temperature, (b) pressure and temperature of separation of water and petroleum, (c) petroleum composition, and (d) petroleum:water ratio (PWR). The results showed that significant dilution and concentration of water samples could occur, particularly at high PWR. It was not possible to establish simple guidelines for identifying good and poor quality samples due to the interplay of the above variables. Sample quality is best investigated using PVT software of the type used in this study.     

塔河油田奥陶系油藏开发动态与地层水化学特征响应

塔河油田是塔里木盆地第一个超亿吨级的大型油田,其主力油藏为奥陶系缝洞型碳酸盐岩油藏.近年来,油田地层水的问题日益突出,严重影响了油田的开发和生产.阿克库勒凸起北部地质历史时期曾经发育间断性的大气水下渗-向心流,凸起南部斜坡区受到泥岩压实排水和粘土矿物脱水形成的离心流的影响,地层水受到一定程度的淡化.塔河油田主体部位处于越流泄水区,地层水具有明显的高矿化度和高K Na 、Cl-浓度,有利于油气聚集成藏.塔河油田奥陶系地层水动力场形成演化与油气运移、聚集密切相关.海西晚期、喜马拉雅期离心流强度大,是油气藏主要成藏期.早、晚海西运动、印支运动期间抬升剥蚀,遭受强烈的大气水下渗淋滤、生物降解,是油气藏主要破坏期.根据地层水赋存状态,区分出洞穴底部油气驱替残留水、洞穴周缘小缝洞系统驱替残留水、储层下部层间水3种不同类型.研究油井产出水矿化度、Cl-、K Na 浓度动态变化规律,总结出平稳型、起伏型、上升型和下降型4种动态类型.通过综合分析油井开发动态及油水产出特征,正确把握其变化过程,可以判断油井产水来源,从而为油田的稳油控水提供指导性建议.     

冀中廊固凹陷油气输导体系类型与成藏模式

针对目前廊固凹陷油气成藏机制不够清晰,油气运移和输导体系仍不明确等问题,首先从反映油气运移和输导体系通道的参数筛选入手,重点分析含蜡量和油田水矿化度随埋深的变化规律,进而根据其垂向的分布组合样式,总结出A型(常规层析型)、B型(快速通道型)和C型(孔隙—裂缝型)3种油气藏输导体系类型,并按构造区带分析了不同输导体系约束的油气藏的空间展布特征。然后研究输导体系对油气藏的深度、规模、类型和相态的控制作用。最后根据输导体系类型划分方案建立了4种成藏模式,为油气勘探方向和勘探目标的预测提供重要依据。     

苏丹Muglad盆地FN油田沥青垫的确认及成因分析

Fula坳陷位于苏丹 Muglad盆地东北部,面积约 5 000 km2,已发现有较大规模的油气储量.FN油田是到目前为止该坳陷发现的最大油田,储量近亿吨,主要储层是上白垩统 Aradeiba组和下白垩统 Bentiu组.油田地质地球化学研究表明,水洗和生物降解作用是稠油形成的主要原因.该油田普遍发育有沥青垫,开发难度较大.对该油田两口井原油和油砂详细的地球化学分析以及对沥青垫成因的探讨,为进一步的油气勘探开发提供了决策依据.     

ArcGIS下的油田勘探资料管理方案

在长期的石油勘探工作中积累了包括地震、测井、地质以及其它非震地球物理方法等方面的大量资料。对这些与空间信息密切相关的资料进行数字化管理的理想方案是通过地理信息系统平台实现。油气勘探数据管理系统选用ArcGIS平台。用商业DBMS如oracle8作为数据库服务器，采用三层式C／S结构，用ESRI的Geodatabase模型和ArcSDE建立分布式勘探地理数据库。整个勘探地理数据库按专业或专题分为若干子库，每个子库都可以位于地理位置不同的专业数据服务器上，通过油田内部宽带网连接。制订勘探资料元数据标准，并根据元数据标准编制元数据同步程序和编辑器，实现油田勘探资料的规范化管理。     

某油田地下水污染特征及其机理分析

在对某油田石油类污染物分布特征研究的基础上,对其进入地下水的途径进行分析。研究表明,除石油类外,CODMn、Cl-、NO3-N和TDS具异常变化,这些异常变化已成为石油类污染的参考指标。含水层污染程度主要以严重污染和中度污染为主,下段含水层中的石油类污染物的浓度明显高于上段含水层。地下水遭受污染的途径类型分为地表渗透型和优势通道渗漏型,但地表渗透型污染对研究区地下水的威胁性相对来说较小。由构造活动、地下水开采引发的地裂缝形成的优势通道渗漏型污染是地下水污染的主要途径。     

吉林油田红岗北地区低阻油层评价技术

吉林油田红岗北地区部分井区油层电阻率相对较低,对测井油、水层解释造成了困难。利用岩心、测井及试油资料,分析形成低阻油层的主要因素是束缚水含量高,另外地层水矿化度高、淡水泥浆侵入、富含导电矿物等也是造成低阻的原因。因此,利用核磁测井资料建立了束缚水饱和度模型,形成了低阻油层的解释方法及标准,在实际应用中见到了较好的效果。