Microbial and Waterflooding of Fractured Carbonate Rocks: An Experimental Approach

Fractures and fractured zones require special attention while formulating a reservoir development plan. They may improve or hinder the oil production. Conductive fracture rocks may provide the required permeability to drain an oil saturated low permeability rock matrix. Low sweep efficiency of many oil reservoirs is the result of channelling of injected water through high permeability zones that are normally associated with naturally fractured systems in heterogeneous reservoirs. In this case, a substantial amount of effort needs to be focused on improving the distribution of injected water in the wellbore through different treatments, such as using gelling agents, cements, cross-linked polymer and emulsions. Other alternatives such as microbial and surfactant based methods have been proposed. This paper presents the results of research conducted on thermophilic bacteria that were obtained from UAE local environment. Coreflooding experiments were conducted on fractured single cores to show the effectiveness of microbial treatment. Different fracture angle orientations of 45°, 90°, and 180° relevant to the axis of the flow were investigated. The effect of matrix permeability on the treatment was also studied. A comparison between water flooding and microbial flooding of fractured systems was conducted. A non-invasive imaging technique—Scanning Electron Microscopy (SEM)—was employed to visualize changes on the surface of the fracture as a result of bacteria flow through the system.     

含油气盆地断层封闭性研究探讨

论述了断层封闭性研究中断层封闭机理、地应力与断层封闭性、断层的伴生构造、断块的封闭性等方面的一些新进展和断层封闭性评价的可靠性，并对其中断层封闭性的双向性、非均质性以及碳酸盐岩的封闭性等问题进行了探讨，指明了进一步研究的方向。     

湿式搅拌磨细磨重质碳酸钙的实践和微粉加工工艺

介绍了ＧＳＤＭ－４００型超细盘式搅拌磨细磨不同产地重质碳酸钙的工艺实践，阐述了造纸涂布级重钙微粉的超细加工工艺，分析了各种工艺的特点和选择依据。     

孔隙性碳酸盐岩储集层分类的模糊物元关联分析法

提出了一种孔隙性碳酸盐岩储集层分类的新方法,即模糊物元关联分析.实例表明与其他方法一致,并与实际相符,可推广使用.     

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〗塔里木盆地和田古隆起区下古生界发育灰岩、白云岩两类储层。灰岩储层类型有灰岩溶蚀孔隙（孔洞）型储层、灰岩岩溶缝孔洞型储层和构造裂隙型储层。灰岩溶蚀孔隙（孔洞）型储层发育与加里东期、海西期不整合面没有密切的关系; 储渗空间发育受组构控制; 属低孔低渗、储集性较差的储层。灰岩岩溶缝孔洞型储层发育分布与加里东期、海西期不整合侵蚀面有着密切的关系; 发育分布非均质性强。灰岩构造裂隙型储层可发育高角度斜交或垂直层面的部分充填和未充填构造裂隙。白云岩内发育晶间孔及晶间溶孔、溶蚀孔洞、大型洞穴、风化裂隙、构造裂隙等5种储渗空间，它们构成白云岩岩溶缝孔洞型、白云岩溶蚀孔洞型两类储层。白云岩岩溶缝孔洞型储层发育与加里东期、海西期不整合面有着密切的关系; 其涉及厚度较小。白云岩溶蚀孔洞型储层的发育具有普遍性; 与加里东期、海西期不整合面关系不密切; 非均质性明显。白云岩溶蚀孔洞型储层在寒武系及下奥陶统广泛发育, 孔隙度较高, 渗透率较低，是该区最值得勘探的储层类型。     

川东三岔坪潜伏构造石炭系储层特征及有利区预测

通过对川东三岔坪潜伏构造石炭系储层特征的研究,发现储集空间以溶孔及晶间孔为主;储集类型属裂缝-孔隙型;纵向上以Ⅲ类储层为主,Ⅱ类储层呈局部分布(具有2个相对的高孔带);储层的主要控制因素为溶蚀及构造作用。采用改进曲率及地震方法对石炭系储层进行了综合预测后指出,早期认为的石炭系储层缺失区并不存在,有利储层分布区呈局部的点团状或条带状分布并且是该区下步勘探及井位部署的重点区域。     

塔里木盆地塔中北坡奥陶系碳酸盐岩岩溶储层的形成机理

塔里木盆地塔中北坡奥陶系碳酸盐岩储层已成为该盆地油气勘探的重要目标之一,目前对于该岩溶储层的溶蚀机制尚存在争议。为此,基于沉积、层序与储层综合研究成果,结合微观分析测试与宏观地震资料分析结果,将该区碳酸盐岩岩溶储层划分为石灰岩溶蚀孔洞型、白云岩孔洞型和硅质岩裂缝孔洞型3种类型,并分别探讨了其形成机理。结果表明:(1)石灰岩溶蚀孔洞型储层纵向上分布在中奥陶通鹰山组上段和一间房组,而白云岩孔洞型储层主要发育在下奥陶统蓬莱坝组和鹰山组下段且厚度较大;(2)石灰岩溶蚀孔洞型储层形成于三级层序界面(低位期)岩溶作用,而白云岩孔洞型储层则主要形成于受三级层序界面岩溶作用控制的深埋藏白云石化作用,两者均分布在三级层序界面之下的高位体系域;(3)该区硅质岩储层的发育明显受断裂控制,是深部热液沿断层对石灰岩改造的结果,硅质岩储层及其热液溶蚀缝洞系统分布在断裂附近。进而推测:塔中北坡奥陶系除了发育上述3种储层类型以外,还发育台地边缘礁滩型储层。     

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??The Ordovician carbonate rocks in the Gucheng area are the potential replacement zone for oil and gas exploration in the Tarim Basin. However, its sedimentary sequence has been less studied, which restricts the progress of oil and gas exploration in this area. In this paper, based on the cyclic changes of the carbon isotope value, together with the analysis of logging curves and well-seismic calibration, the Ordovician carbonate strata were divided into 4 third-order sequences. According to the six types of microfacies (i.e. calcsparite cemented grain limestone, algal-cemented calcarenite, packstone, micrite limestone, medium-coarse crystalline dirty dolomite, and fine powder crystal dolomite) identified under microscopic observation of thin sections, the distribution and evolution law of sedimentary systems in the sequence were analyzed. The following results are obtained. First, the platform margin–semi-restricted platform and platform margin–open platform sedimentary systems developed in this area. Both OSQ1 and OSQ2 are predominantly sea-level falling half-cycle sequences, and platform margin limestone and semi-restricted platform dolomite are dominant. Second, OSQ3 is predominantly sea-level rising half-cycle sequence. In the early stage of sea-level rising, platform margin–semi-restricted platform developed, and later platform margin-open platform developed. Third, OSQ4 is composed of sea-level rising half cycle and platform margin–open platform limestone developed. It is concluded that the sea-level rising/falling cycle controlled the distribution and evolution of sedimentary system in the sequences in this area. In the sea-level falling stage, semi-restricted platform best developed in OSQ1 and OSQ2, recording as the main horizons for the development of dolomite.     

Effect of steam content and O2 pretreatment on the catalytic activities of Au/CeO2–Fe2O3 catalysts for steam reforming of methanol

The Au/CeO₂–Fe₂O₃ prepared by deposition–precipitation were studied by steam reforming of methanol at a reaction temperature range of 200–400 °C. Complete methanol conversion was obtained at the optimal steam/methanol ratio of 2 at 400 °C. A high steam content strongly depressed both methanol conversion and hydrogen concentration since this led to a complex mechanism and the formation of carbonate and formate species. After pretreating with oxygen, the catalytic activity dramatically decreased with the presence of an inhomogeneous Ce_xFe_1−xO₂ solid solution phase; the covering Au sites by the free α-Fe₂O₃ particles; and an agglomeration of both free α-Fe₂O₃ and Au particles.     

碳酸盐岩储层叠前逆时偏移及GPU/CPU异构计算方案研究

针对碳酸盐岩储层地质构造的特点,提出采用基于声波方程的叠前逆时偏移算法对其进行成像,并在偏移过程中引入优化差分系数和完全匹配层(PML)边界条件来提高波场的数值模拟精度,同时利用GPU/CPU异构并行加速技术对算法进行优化,从而显著提升偏移的计算效率。模型测试表明,与传统差分系数相比,同阶的优化差分系数具有更高精度,压制频散效果明显;PML边界条件能够有效的吸收边界反射,减少边界反射对有效波场的干扰;叠前逆时偏移方法可有效识别碳酸盐岩模型中的小尺寸孔洞和裂缝,归为准确,刻画清晰,对碳酸盐岩储层成像具有显著优势;GPU/CPU异构并行加速技术可明显提高偏移的计算效率,与传统CPU算法相比,加速比可达60倍,对于实际推广应用具有重要意义。