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101.
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Fatma Taktak Adel Rigane Taoufik Boufares Samir Kharbachi Samir Bouaziz 《Journal of Petroleum Science and Engineering》2011,78(2):376-383
Oil production based on reserves in place in the Ashtart oilfield required the precise knowledge of the main reservoir parameters including porosity, permeability and irreducible water saturation. The reservoir series is comprised of Nummulitid but heterogeneous limestones of the El Garia Formation, the petrofacies texture, geometry and petrophysical parameters of which were apprehended using seismic profiles; gamma-ray and sonic lateral logs, as well as cores and cuttings taken in drillwells. The evaluation of residual oil saturation, multiphase flow and oil production techniques from the Ashtart reservoir also depend on variations and zoning of the irreducible water saturation. Estimation of the initial water saturation and hence variations in the capillary pressure in the reservoir, required compilations of porosity data measured on cores, supplemented by additional but computed porosities based on acoustic log diagrams. Furthermore, Gamma Ray, Sonic log, and well to well correlations tied to core results and well cuttings, help recognize the layered lithologies within the El Garia flat lying but stratified, Ypresian in origin reservoir rocks. Abundant permeability and porosity values compiled in the light of seismic sequence and Gamma Ray and Sonic log details, were integrated in an empirical approach using the Leverett J function, to model the irreducible water saturation depending on the capillary pressure distribution in the whole reservoir. Variations of this principal hydraulic parameter in a wide range (Swir: 12 to 40%) compared to the preceding lithostratigraphic, petrographical and petrophysical results help recognize four main rock pore types in the commercial Ashtart reservoir. These vary from (1) a zone with a rock pore type showing an irreducible water saturation as low as 12%, and a fairly good reservoir character in the lower third part of the lithologic column which is thought to channelize a multiphase fluid flow in the global oilfield, (2) to those zones built-up of rock pore types with higher initial water saturation amounts which in certain cases tend to indicate zones of degraded reservoir. Our study suggests that diagenesis prevalently controls porosity, due to operative dissolutions of the Nummulitid tests/bioclasts, and cementation; moreover, diagenesis exerts effects on permeability by interconnecting intergranular and intratest pore spaces. In contrast, microfracturing enhances permeability of the reservoir. This is notably the case in the fairly permeable central zone in the Ashtart reservoir with excellent petrophysical parameters, but which were found to degrade gradually towards its peripheries. 相似文献
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对埋地管道下部泄漏油品在雨前、雨中和雨后的不同水分分布土壤中油品渗透扩散进行模拟分析,借助CFD软件建立土壤多孔介质中油水两相流动的三维流动传质耦合模型。模拟计算结果表明:油品在地下渗透扩散范围受水分分布影响明显,泄漏油品在下雨前的土壤中地下扩散区域以不倒翁状向四周渗透;雨中泄漏油品受雨水冲带后在地下四处流窜并以极不规则形状区域向四周扩散;雨后泄漏油品以烧瓶状区域向四周扩散。在雨前、雨中和雨后三种工况下,扩散速率稳定后,雨后的泄漏范围及地表扩散面积均是最小;雨中油品泄漏范围最大且增长速率比雨前高约3%;雨前油品地表扩散范围最大且增长速率比雨中高约2%。 相似文献
104.
A direct foaming method of dispersed suspensions containing muscovite particulates and a glass powder (47BaO-21B2O3-27SiO2-5Al2O3, in mol%) is used to prepare porous ceramic structures. The sintered foams exhibit extremely low thermal conductivity and slight expansion during the thermal treatment at 1000 °C. Both the foam stability and its thermal conductivity are investigated by considering foaming agents, muscovite/glass ratios, solid contents, microwave drying, wetting behaviors, and foam consolidation. One of the muscovite/glass ceramic foam, thermally treated at 950 °C for 1 h, showed the lowest thermal conductivity of 0.18 W m−1 K−1 at 800 °C among all of the prepared samples. Its gas permeability and compressive strength are 0.1 × 10−7 cm2 and 440 kPa, respectively. 相似文献
105.
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在气井产能试井过程中,通常人们把井筒储集效应消失后的二项式系数B认为是恒定常数,但实践却证明,由此确定的二项式系数B误差较大。文章基于气井二项式产能方程通式,考虑探测半径及对应渗透率的变化,从理论上推导了二项式系数B的变化规律。完整、准确地说,二项式系数B受探测半径及对应渗透率的影响,只不过在井筒储集效应阶段系数B变化明显,当探测半径扩大到一定程度(当然井筒储集效应已经消失),二项式系数B受探测半径及对应渗透率的影响越来越小,逐渐趋于一恒定常数。这对加深理解二项式系数B及产能试井合理设计、得到稳定可靠的产能方程和无阻流量起到了重要指导作用。 相似文献
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针对西峰油田特低渗透油层,通过对储层的物性特征、储层敏感性矿物、地层水性质的分析研究和室内敏感性评价实验,初步搞清了钻井完井液对特低渗透储层的伤害机理,确定了完井液施工措施,并研制出一种新型的水平井低伤害完井液体系,在庄平3井进行了试验,应用效果良好。 相似文献
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