Petrographic and petrophysical characterization of some Paleozoic rocks,Um Bogma area,Southwest Sinai,Egypt

Sixty-two samples were collected from the five formations at Um Bogma area, (Southwest Sinai, Egypt). Nine samples were collected from Sarabit El Khedim Formation, ten samples were collected from Abu Hamata Formation, eighteen samples were collected from Adedia Formation, eight samples were collected from Um Bogma Formation and eighteen samples were collected from Abu Thora Formation.The Paleozoic rocks at Um Bogma area, consist mainly of sandstones, siltstones, shales, limestone and dolostones, which are unconformably overlie igneous and metamorphic rocks (granite, diorite and gneiss) of Precambrian age.The petrographic studies were applied to identify different rock units, different facies and its diagenetic history and to reveal its effect on the storage capacity properties. Different types of porosity (oversized, intergranular, fracture and vuggy porosities) have been identified based on the petrographic investigation of the studied thin sections.The Paleozoic sandstone rock samples are characterized by porosity average about 19% for Facies 1 (quartz wack) and about 18%for Facies 2 (quartz arenite) and permeability average 420?mD for Facies 1 (quartz wack) and 690?mD for Facies 2 (quartz arenite), so these rocks can be considered as good reservoir rocks. The Paleozoic carbonate rock samples (Facies 3) are characterized by poor porosity (less than 7%) and very low permeability (less than 0.5?mD), which caused by matrix and diagenetic processes and refer to bad reservoir rocks.Porosity can be linked to the two derived electrical properties (formation resistivity factor and electrical tortuosity) of the studied Paleozoic rocks at Um Bogma area. The electrical tortuosity has significant effects on both permeability and formation resistivity factor. The permeability decreases with increasing electrical tortuosity and the relation between both of them is inverse relationship with good coefficient of correlation. The permeability decreases with increasing electrical tortuosity and the relations between both of them are inverse relationships with high coefficient of correlation. The formation resistivity factor increases with increasing electrical tortuosity and the relations between both of them are positive relationships with a fair to very high coefficient of correlation.     

Study of pertrographical and electrical properties of some Jurassic carbonate rocks,north Sinai,Egypt

The Jurassic sedimentary section in north Sinai is of a special interest in particular for its economic potentiality. The understanding of petrographical and electrical properties of these rocks is essential for investigating minerals and oil and water exploration. This paper presents a study of the petrographical and A. C. electrical properties of Jurassic carbonates. Electrical measurements have been conducted for twenty-nine (18) carbonate samples. The slight changes between samples in electrical properties were attributed to the changes in mineral composition, texture pore spaces and pore throat distribution of the samples. Electrical properties generally change with many factors (grain size, mineral composition, grain shape and facies). The dielectric constant decreases with frequency and increases with the presence of conductive solids (silt and clay) and its composition. The conductivity increases with the increase of conductor paths between electrodes. The main goal of this paper is to shed more light on interrelations between electrical properties (conductivity, dielectric constant and impedance as a function of frequency), petrography and mineral composition (carbonates that contain clays and quartz grains).     

Anisotropy of permeability,P-wave velocity and electrical resistivity of Upper Cretaceous carbonate samples from Tushka Area,Western Desert,Egypt

Petrophysical properties (such as porosity, permeability, grain density, bulk density, electrical resistivity, and P-wave velocity), as well as the anisotropy of the permeability, seismic velocity (P-wave velocity) and electrical resistivity were characterized in 42 carbonates (limestone) rock samples, collected from shallow wells (seven wells encountered the Upper Cretaceous carbonate rocks with variation in thickness, where well 1 encountered 50 ft thick Nubian sandstone, which decreased to about 30 ft thickness in well 7) from Tushka area, Egypt.The petrographic investigation of the studied carbonate rock samples shows three microfacies associations: Facies1 (MFA-1) is mainly an oolitic, low dolomitic and low glauconitic, fossil-rich packstone with a tendency towards floatstone or rudstone, Facies 2 (MFA-2) is mainly a glauconite rich, low dolomitic floatstone with some tendencies towards rudstone and Facies3 (MFA-3) is mainly a sparry calcite-cemented, low dolomitic rudstone rich in glauconite and iron minerals.The MFA-2 with the lowest average density and highest average porosity is characterized by a strong anisotropy of both permeability and electrical resistivity. The values of the anisotropy ratio of seismic velocity (P-wave velocity) are close to one for all facies, this means that no anisotropy can be detected in the seismic velocity. A comparison between the coefficients of anisotropy reveals that the anisotropy of electrical resistivity and permeability are related to each other.     

Mutual relations between petrographical and petrophysical properties of Cretaceous rock samples for some wells in the North Western Desert,Egypt

The petrographical and petrophysical analyses are very important to understand the factors controlling the reservoir quality. So, these techniques have been applied on rock samples collected from the Cretaceous section for four wells drilled in the North Western Desert, Egypt. The wells are Gibb Afia-1, Betty-1, Salam-1X and Mersa Matruh-1. Lithostratigraphically, the studied rock samples are grouped into Lower Cretaceous sandstones, Upper Cretaceous sandstones and Upper Cretaceous carbonates.Petrographically, the Cretaceous rock samples can be differentiated into 14 microfacies, namely, chloritic ferrigenous quartz wacke, ferrigenous calcareous quartz wacke, laminated quartz wacke, calcareous glauconitic quartz arenite, laminated gypsiferous quartz arenite, fossiliferous glauconitic calcareous quartz arenite, clayey ferrigenous calcareous quartz arenite, ferrigenous calcareous glauconitic lithic arenite, feldspathic ferrigenous quartz arenite, fossiliferous biomicrite, glauconitic oolitic sandy biosparite, calcareous gypsiferous ferrigenous dolostone, calcareous algal siltstone and laminated sandstone and siltstone.Lower Cretaceous rocks have been deposited in a fluviatile in shallow marine environments, while the Upper Cretaceous rocks have been deposited in a fluviatile in marine environments. Diagenetic history has been controlled by diagenetic processes enhancing the porosity (dissolution of framework silicates, leaching and dolomitization) and diagenetic processes reducing porosity (mechanical infiltration of clays, formation of authigenic minerals, compaction and pressure solution, cementation and recrystallization).Porosity types are mainly interparticles, vugs and molds, in addition to fractures and channel porosities. The average porosity of the Lower Cretaceous sandstones, Upper Cretaceous sandstones and Upper Cretaceous carbonates are 16.6%, 16.7% and 22.0%, respectively, as depends mainly on the bulk density with average values of 2.22, 2.26 and 2.14 g/cm³, respectively.The permeability of both the Lower and Upper Cretaceous sandstones with average values of 114.14 and 50.40 mD, respectively, depends mainly on porosity with some other parameters, like pore throat sizes and it could be also related to the electrical tortuosity with average values of 2.27 and 2.40, respectively. The Upper Cretaceous carbonate rocks are characterized by high porosity (22.0%) and low permeability (3.91 mD), this could be attributed to the isolated pore space, and decreasing in pore throat sizes due the presence of significant amounts of fine particles (clay minerals having microporosity and reduce the pore throat radius).The reservoir quality index with average values of 0.43, 0.29 and 0.08 μm, depends mainly on permeability with average values of 114.14, 50.40 and 3.91 mD, of the Lower Cretaceous sandstones, Upper Cretaceous sandstones and the Upper Cretaceous carbonates, respectively. This indicates that, the sandstones of the Lower and Upper Cretaceous rocks are characterized by high to moderate reservoir quality, respectively, while the Upper Cretaceous carbonate rocks are characterized by low reservoir quality. This may be due to the combined effect of the porosity and permeability rather than the total porosity.The formation resistivity factor was measured at three consequent saline concentrations of 6, 30 and 60 kppm, it is controlled by the porosity and electrical tortuosity.     

碳酸盐岩储层渗透率与孔隙度、喉道半径的关系

碳酸盐岩储层渗透率与孔隙度的相关性差,与喉道半径的相关性较好,但喉道半径的分布范围通常较大,究竟哪一种喉道半径对渗透率起主要的控制作用,对此还没有形成统一的认识。为此,有必要探讨碳酸盐岩储层渗透率与喉道半径之间深层次的关系,建立渗透率、孔隙度、喉道半径三者之间的关系模型。根据碳酸盐岩储层非均质性强、孔隙结构差异较大的特点,利用毛细管压力曲线特征参数对研究样品进行了分类,针对不同孔隙结构的样品分别研究上述三者之间的关系,避免了把所有样品放在一起研究而掩盖掉非均质性影响的情况。通过对压汞实验基本原理的深入分析,认为毛细管压力曲线的拐点所对应的喉道半径对渗透率起主要的控制作用,并首次提出了拐点喉道半径的概念。将各种喉道半径与渗透率进行相关性分析,证实了拐点喉道半径与渗透率的相关性最好,最终建立了拐点喉道半径与渗透率、孔隙度三者之间的关系模型。利用该模型计算的渗透率与岩心分析渗透率相关性较好,相关系数达到0.79。     

Study on P-wave and S-wave velocity in dry and wet sandstones of Tushka region,Egypt

Acoustic laboratory measurements have been conducted for forty-two sandstone samples at fully air and water saturation. This study is an attempt to learn more about the behavior of both P-wave and S-wave velocity in porous sandstone rock samples for both dry and wet conditions.The statistical analysis indicates that higher values of the P-wave velocity are obtained for saturated samples and lower values are obtained for dry samples. The average P-wave velocity of dry rock samples is 2766 m/s and the average P-wave velocity of wet rock samples is 2950 m/s. The S-wave velocity is higher in the dry state with an average value of 1585 m/s. The average S-wave velocity of wet rock samples is 1357 m/s.The derived equations can be used for the prediction of P-wave velocity of wet rock samples from the P-wave velocity of dry rock samples, and the S-wave velocity of wet rock samples can be predicted from the S-wave velocity of dry rock samples. A strong linear correlation between P-wave velocity and S-wave velocity of dry rock samples and between P-wave velocity and S-wave velocity of wet rock samples was found. The resulting linear equations can be used for the estimation of S-wave velocity from the P-wave velocity in the case of both dry and wet rock samples.     

和田河气田碳酸盐岩岩心裂缝分维数及与物性的关系

世界60％的油气可采储量赋存在碳酸盐岩储集层中,而我国已探明的碳酸盐岩油气储量还不到总储量的10％,研究碳酸盐岩储集层裂缝的发育和分布极其重要,研究表明,岩石的破裂过程具有随机自相似性,岩石裂缝的分维数反映其分形分布特征^[1-4],直接影响着岩石的力学性质和渗流能力,因此分形分析对裂缝性油气藏的勘探开发十分重要,和田河气田是塔里木盆地已发现的大型碳酸盐岩气田,奥陶系为主要产层,储集空间主要是裂缝也孔洞,笔者以该气田为例,尝试性地应用分形理论分析气田岩心资料,定量描述裂缝的发育程度,5寻找裂缝分维数与碳酸盐岩物性的关系,希望能对我国碳酸盐岩储集层研究和勘探有所帮助。     

柴达木盆地英雄岭构造带古近系湖相碳酸盐岩沉积模式、演化与分布

基于野外露头、钻井、岩心、岩石薄片及实验数据,对柴达木盆地英雄岭构造带古近系下干柴沟组上段湖相碳酸盐岩的类型、演化规律和沉积模式进行了系统研究,并结合井-震资料分析和古地貌恢复,对其岩相古地理的平面分布特征进行了刻画,指出了下一步的有利勘探方向。研究表明:英雄岭构造带下干柴沟组上段主要发育藻灰岩、颗粒灰质白云岩、泥晶灰质白云岩3类碳酸盐岩,多具有混积特征,从早至晚经历了半咸化、咸化和盐湖3个沉积演化阶段;由于矿物组分及岩石结构的差异,湖相碳酸盐岩的储集性能呈现较强的非均质性,其中,藻灰岩的储集性能相对最好;储层的岩相组合在垂向上主要存在3种类型,分别发育于湖盆的不同位置。研究建立了凹隆型和缓坡型2种沉积发育模式,指出湖平面的升降频率及陆源碎屑输入量控制不同岩相的单层厚度,微古地貌控制不同岩相组合的平面分布。恢复的下干柴沟组上段沉积早、晚期的岩相古地理特征显示,泥晶灰质白云岩+颗粒灰质白云岩组合主要分布在英西—干柴沟—游园沟缓坡沿岸区和隆起区,其平面叠合面积约为600 km²,是下一步寻找常规油气藏的有利勘探方向;纹层泥晶灰质白云岩主要分布在游园沟及其以东地区的半深湖相凹陷区,其平面叠合面积可达2 500 km²,是下一步寻找非常规源内油气藏的有利勘探方向。     

北部湾盆地乌石凹陷始新统储层特征及主控成因分析

乌石凹陷是北部湾盆地主要生烃凹陷之一,然而始新统优质储层主控因素和展布范围不清是制约研究区有效开发的主要地质问题.为此,本文采用从微观到宏观、从特征到成因、从定性到定量的研究思路,从沉积方面、成岩方面和构造活动的特殊性上探讨始新统不同类型储层的主控因素.分析认为埋藏深度、优势沉积相带、次生孔隙发育带是影响研究区储层发育...     

高过成熟海相碳酸盐岩抽提物不寻常的正构烷烃分布及其成因

鄂尔多斯盆地中部气田下奥陶瓷统马家沟组和四川盆地威远气田上震旦统灯影组碳酸盐岩烃源岩样品氯仿抽提物正构烷烃普遍以双峰型为特征；前峰群主峰多为C17、C19、C20或C21，后峰群主峰多为C25、C27或C29；绝大多数样品以前主峰为最高峰，含有较高浓度的蜡质烃（C22 ），C21-/C22 ，比值为0.50～2.75（平均1.27），华北地区西部和南部露头及浅井的震旦系、寒武系和奥陶系碳酸盐岩烃源岩样品氯仿提取物正构烷烃以高碳数占优势的单峰型为特征，主峰碳为C25、C27和C29，蜡质烃含量高，C21-/C22 比值为0.14～0.90（平均0.36），上述样品的正构烷烃在高碳数普遍具明显奇碳优势。华北地区蓟县震旦系低成熟腐泥型下马岭组灰质页岩干酪根和从前寒武纪繁衍至今的浮游蓝藻（Spirulina subsala）的生烃模拟实验结果共同表明，上述高-过成熟碳酸盐岩抽提物中不寻常分布的正构烷烃可能主要来源于其源岩中的藻类。     

埃及西沙漠盆地中生界烃源岩特征及剩余资源分布

西沙漠盆地是埃及三大主要含油气区之一,已发现大量的油气田,现处勘探发现中期,预探风险增大。为此,在详细评价盆地烃源岩地球化学特征基础上,运用盆地数值模拟技术定量分析剩余资源潜力。研究认为,中侏罗统Khatatba组Safa段和Zahra段煤系暗色泥页岩以及上白垩统Abu Roash组AR-F段暗色泥页岩是盆地的3套主力烃源岩,各凹陷烃源岩广泛分布,厚度变化较大。Khatatba组烃源岩TOC含量在0.5%~10%,裂解烃S₂含量高,为中等-很好烃源岩;Abu Roash组AR-F段烃源岩TOC主要在0.5%~3%,裂解烃S₂含量中-高,属中等-好烃源岩。这3套烃源岩有机质干酪根类型以混合Ⅱ型为主,其次是Ⅲ型,少量为Ⅰ型。指出Khatatba组2套烃源岩全盆处于热演化成熟大量生排烃阶段,凹陷中心达高熟生烃、局部过熟生气阶段,油气并生;Abu Roash组AR-F段烃源岩仅Abu Gharadig和Natrun凹陷进入成熟生烃阶段。提出盆地北部地区主要由侏罗系Khatatba组烃源岩供给油气,东南部地区则有侏罗系Khatatba组和白垩系AR-F段双源供烃。计算表明,盆地剩余可采资源量达6.51×10⁸ t,剩余资源潜力很好;其中,南部Abu Gharadig凹陷古生界、侏罗系和下白垩统AEB,北部Matruh凹陷古生界、Faghur凹陷上白垩统,油气探明程度低,剩余资源可观,为下步勘探的有利方向。     

Burial and thermal history simulation of the subsurface Paleozoic source rocks in Faghur basin,north Western Desert,Egypt: Implication for hydrocarbon generation and expulsion history

Paleozoic Zeitoun, Desouqy and Dhiffah formations represent source rocks to hydrocarbon in Faghur basin, north Western Desert, Egypt. They are characterized by a sufficient amount of organic matter belonging to kerogen type III and mixed type II/III, which are in maturation stage. A 1D-basin modeling was performed by using geological and geochemical data of the Paleozoic source rocks from five wells in Faghur basin, north Western Desert, Egypt. These data used in 1D basin modeling for constructing and understanding of burial and thermal geo-histories of Faghur basin and for simulating and predicting the timing of petroleum and expulsion for the Paleozoic source rocks in the studied wells. Burial and thermal history models indicate that the Zeitoun Formation entered onset of oil generation in the studied wells during Late Cretaceous (100.10–91.65 my) with transformation ratio (TR) 10–25, peak oil during Late Cretaceous (91.65–79.30 my) with TR 25–50 and late oil stage at Late Cretaceous (79.30 my-0) to present day with TR 50–60.45. Desouqy Formation entered onset of oil generation also during Late Cretaceous (94.43–73.60 my) with TR 10–25 in the studied wells, peak oil during Late cretaceous (73.60–62.40 my) with TR 25–50 and Late oil stage during Late Cretaceous to present day (62.40 my-0) with TR 50–61.82. Dhiffah Formation entered onset of oil generation in the studied wells during Early to Late Cretaceous (102.11–92.27 my) with TR 10–25, peak oil during Late Cretaceous (92.27–86.40 my) with TR 25–50 and late oil stage at Late Cretaceous to present day (86.40 my-0) with TR 50–67.27. No cracking oil to gas in the studied Paleozoic source rocks in the studied wells. These basin modeling results also suggest that the Paleozoic source rocks act as an effective source rock where a significant amount of petroleum is expected to be generated and expelled to any nearby prospect reservoir rocks in the Faghur basin.     

塔里木盆地中下奥陶统碳酸盐岩地球化学特征及其对成岩环境的指示——以巴楚大板塔格剖面和阿克苏蓬莱坝剖面为例

利用薄片、碳氧稳定同位素、微量元素等测试资料,以巴楚大板塔格与阿克苏蓬莱坝剖面中下奥陶统碳酸盐岩为研究对象,系统报道了岩石学与地球化学的各种特征,分析了不同特征所表征的成岩环境。研究表明：(1)碳、氧同位素垂向上整体表现为埋藏成岩环境,鹰山组顶部、蓬莱坝组中部以及顶部呈现出淡水成岩环境特征,鹰山组中部与蓬莱坝组底部显示为海水成岩环境,鹰山组下部和上部表现为海水成岩环境背景下短期受到淡水影响,白云岩δ¹⁸O值、δ¹³C值高于灰岩,鹰山组白云岩δ¹³C值低于蓬莱坝组白云岩;(2)不同类型白云岩Sr含量呈现规律性。还原环境敏感元素富集在鹰山组中—粗晶白云岩与蓬莱坝组顶部粉—细晶白云岩,氧化环境敏感元素富集在鹰山组藻砂屑云质灰岩、蓬莱坝组细晶夹自形中晶白云岩和砂屑幻影白云岩;(3)白云岩化的过程是LREE亏损的过程。一间房组生屑灰岩具较高的∑REE,MREE略富集,Ce负异常程度高,蓬莱坝组下部残余结构云岩REE配分继承颗粒灰岩。鹰山组下部藻泥晶砂屑灰岩与云质砂屑灰岩REE配分相似,∑REE具有随水体深度增加而减小的趋势,LREE富集,HREE亏损,Gd正异常。鹰山组中—粗晶白云岩与蓬莱坝组顶部粉_细晶白云岩REE配分相似,MREE富集。鹰山组与蓬莱坝组细晶—中晶白云岩具明显Eu负异常。     

北部湾盆地涠西南凹陷始新统流沙港组一段低渗储层特征及控制因素

为明确北部湾盆地涠西南凹陷始新统流沙港组一段储层特征及物性主控因素,综合应用壁心、薄片、物性、荧光、扫描电镜等储层分析资料,通过对储集特征、物性特征以及沉积作用、成岩作用、构造作用与油气成藏耦合等分析,表明涠西南凹陷流一段储层以长石岩屑石英砂岩和岩屑石英砂岩为主,总体成分成熟度和结构成熟度较低,储集空间主要为原生粒间残余孔和次生溶孔。涠西南凹陷北西源汇区和西部源汇区流一段多为中孔、中—高渗储层,东部源汇区主要为低孔低渗储层。沉积作用造成粒度、分选、泥质杂基等的差异,压实、碳酸盐胶结、有机酸溶蚀等成岩作用是低渗储层物性主控因素;而构造作用和油气成藏耦合所控制的早期烃类充注、异常高压可保护原生孔隙,加上断裂派生的裂缝可对低渗储层物性进行改善。涠西南凹陷北西源汇区和西部源汇区流一段储层由于埋深较浅,其水动力较强、粒度较粗、分选较好,在泥质杂基较少的区域储层物性较好;而东部源汇区在靠近生烃主洼的二号断裂附近,存在早期烃类充注、有机酸的强溶蚀以及部分高压保护,在2 500~3 500 m形成次生孔隙和高压孔隙发育带,亦发育深埋藏有利储层。     

Hydrocarbon potentiality, burial history and thermal evolution for some source rocks in October oil field, northern Gulf of Suez, Egypt

This paper attempts to apply a one dimensional model on four source rocks (Belayim, Lower Rudeis, Thebes, and Brown Limestone formations), in East Warda concession, October oil field, throughout the different geological times. Moreover, the fundamental aspects of the petroleum system in the study area is evaluated through studying maturation and hydrocarbon potential in order to gain an understanding of onset of oil generation and expulsion. The position of three wells (syn. or pseudo wells) is proposed based on the available geological and thermal data. Also, the existing temperature database is enhanced by using the available temperature data for 220 wells in the Gulf of Suez and the Red Sea, 53 wells in the Mediterranean Sea, 29 wells in the Nile delta, 7 wells in Sinai, 2 wells in Upper Egypt and 39 wells in the Western desert. Finally, the timing of oil generation for Belayim, Thebes, Lower Rudeis and Brown Limestone source rocks in the Northern Gulf of Suez area is updated. From this study we conclude that, the cumulative yield of the Belayim and Lower Rudeis formations is lower than that of the Thebes and Brown Limestone formations.     

川东北地区海相碳酸盐岩三期成烃成藏过程

川东北地区构造运动复杂，导致油气成藏过程复杂，为细化该区油气成藏史，对白云岩储气层中的固体沥青特征、包裹体均一温度、成岩作用等进行了研究。印支期（T2）末，上奥陶统五峰组（O3w）一下志留统龙马溪组（S11）生成大量低熟稠油，此时，上二叠统长兴组（P2ch）生物礁相中孔隙发育，形成储集空间；二叠系（P）烃源岩及O3w—S1l烃源岩在燕山早期（J2）达到生成原油或轻质油高峰，上述两个时期形成的油气包裹体均一温度范围为100～150℃；在燕山晚期（K2）一喜马拉雅期，早期形成的油气藏与烃源岩及分散可溶有机质发生热裂解生成干气，形成现今的天然气（甲烷）藏。因此川东北地区存在三期成烃成藏过程，分别是印支期、燕山早期和燕山晚期。图7表2参26关键词：四川盆地；普光气田；海相碳酸盐岩；成烃成藏过程     

Isopach,lithofacies changes,and source rocks chracteristics of Khatatba and Alam El Bueib formations of some wells in North East Western Desert,Egypt

The present work deals with isopach, lithofacies changes, and source rock chracteristics of Khatatba and Alam El Bueib formations of some wells in North East Western Desert. Isopach and lithofacies changes showed that the thickness of Khatatba Formation increases toward the south western direction and decreases toward northern parts, and the sediments consisting of sandstone and shale facies indicate a shallow marine environment. Alam El-Bueib sediments increase toward the north direction, and argillaceous sandstone facies reflect terrestrial-to-shallow marine environment. The geochemical analysis showed that Khatatba Formation bears a mature source rock and has poor-to-good generating capability for both oil and gas and lie within the early generation window and oil window. Alam El Buieb Formation constitutes a mature source rock and has poor-to-good generating capability for both oil and gas. It can be stated that Khatatba and Alam El Buieb are the main source rock for hydrocarbon accumulations rich with organic sediments and could be considered as effective source rocks for generating hydrocarbons in the the studied wells.     

准噶尔盆地中拐凸起石炭系火山岩岩性测井识别及应用

储层岩性分析是储层评价和油藏勘探的基础。火山岩储层岩性复杂、种类较多,严重影响了油藏的 勘探开发效果。以中拐凸起石炭系火山岩薄片、录井、岩心及岩屑等资料为基础,分析了研究区的主要岩 石类型,建立了岩性与电性的对应关系图版,并结合常规测井交会图识别法来识别岩性,从而归纳、总结 出了研究区火山岩岩性的常规测井响应特征。     

准噶尔盆地乌夏地区中上二叠统碎屑岩成岩作用及次生孔隙演化

准噶尔盆地乌夏地区中上二叠统碎屑岩储层埋藏深,物性差,以次生孔隙为主,成岩作用是影响中深部储层次生孔隙发育的最主要因素。铸体薄片、扫描电镜、X射线衍射等微观研究表明乌夏地区中上二叠统储层碎屑岩成分及结构成熟度均较低,次生孔隙发育,下乌尔禾组和夏子街组的平均孔隙度分别为8.15%和7.85%,其中次生孔隙分别占下乌尔禾组和夏子街组总孔隙的77.18%和80.90%,孔隙增生量平均值分别为6.49%和4.74%。研究区碎屑岩储层主要处于中成岩阶段A-B期,成岩作用以压实作用、胶结作用及溶蚀作用为主,压实作用造成的孔隙度损失平均约为24.5%,胶结作用造成的孔隙度损失平均约为6.14%,溶蚀作用以长石和岩屑颗粒的溶蚀为主,其产生的孔隙增生量对下乌尔禾组和夏子街组的贡献率分别为47.62%和55.86%。研究区受大气水溶蚀、断裂带及有机酸溶蚀作用的影响,在纵向上形成3个次生孔隙发育带。次生孔隙发育带是研究区在低孔低渗条件下寻找相对有利储层的重要区带。     

塔河油田碳酸盐岩储层声学参数特征及变化规律

以塔里木盆地塔河地区碳酸盐岩复杂介质为例,依据地层条件岩石声学参数的实验测试结果,获得下述认识:1)纵横波速度随围压的增大而增大,随温度的升高而降低;2)岩石的动弹模量随着围压的增加而增加,随着温度的增加而减小;3)纵横波的衰减随着围压的增加而减弱,随着温度的增加而增强。