低孔隙度低渗透率岩心欠饱和对岩电实验参数的影响分析

岩电实验首先要求用地层水完全饱和岩心.但对于低孔隙度低渗透率岩心,由于受实验周期的限制,岩心往往不能达到完全饱和.岩心欠饱和状态下对地层因素F和电阻增大率I的测量只能是在一定条件下的近似,存在一定误差,误差的绝对值虽然较小,但相对误差却往往较大.通过理论推导、实验验证,说明了岩心欠饱和因素对岩电实验结果中胶结指数m和饱和度指数n的影响,并给出了校正方法.在岩心不能达到完全饱和的情况下,按照正常操作程序实验,对饱和度指数n会产生影响,通常使n值降低,必须增加1个校正值;在岩心无法完全饱和的情况下,按照正常操作程序实验,会对胶结指数m产生明显的影响,且使m值增大,这种影响可以通过引入1个校正量加以校正.     

渤南洼陷低孔隙度低渗透率地层岩石力学参数测井计算方法

针对胜利油田渤南洼陷低孔隙度低渗透率地层开展了岩石强度测井评价方法研究.以岩石物理学、岩石力学为理论基础,在实验室同步测试岩石强度及声波时差、密度等测井参数.经数理统计分析后建立力学参数计算模型,并将其应用到地层坍塌压力、破裂压力等井壁稳定性评价参数的计算中.与实际钻井工程资料对比表明,所构建的岩石力学参数计算模型对研究工区地层具有较好的适应性,能够给工程设计提供可靠的依据,对提高井身质量、有效保护油气层、降低钻探成本有着重要意义.     

石西地区侏罗系八道湾组低孔渗成因

通过对准噶尔盆地石西地区侏罗系八道湾组碎屑岩储集层特征的系统分析,认为该储集层岩石具有成分成熟度低,结构成熟度较高的特点;成岩作用属渐进埋藏作用,表现为压实作用普遍较强,胶结作用程度弱,主要处于晚成岩的A1期;主要储集孔隙类型以残余粒间孔为主,颗粒溶孔次之。指出岩石中富含千枚岩等塑性岩屑及成岩压实作用较强是造成储集层低渗的主要原因。     

Analyzing the Well Production Data of Composite Dual Porosity Single Permeability Oil Reservoirs

Abstract

Analyzing well production data is one of the important methods for estimating reservoir parameters such as hydrocarbon in place. Recent techniques rely on the use of material balance time to account for variable operating conditions. Many dual porosity reservoirs can be modeled by a composite reservoir. So production data analysis of composite dual porosity single permeability reservoirs is of great interest. Apparently, modern methods have not been applied to complex reservoir models such as composite dual porosity single permeability reservoirs. So the purpose of this article is to analyze production data of such reservoirs with the use of material balance time function.

In the first step, a material balance time function is defined in the same way as the single porosity reservoirs and its applicability is confirmed by converting a constant well pressure solution to a constant well rate solution with the use of this time function. It should be noted that the available type curve matching methods cannot be applied to such reservoirs and in this article data analysis is based on the type curveless method. Furthermore, based on the time when each flow regime is observed, a discussion on the analysis of production data with the use of material balance time function for each case is conducted. Finally, applicability and accuracy of the material balance time method for estimation of oil in place of such reservoirs are demonstrated using synthetic reservoir examples.     

Investigation on the Thermal Expansion of Four Polymorphs of Crystalline CL-20

The thermal expansion behaviors of α-CL-20 · 1/2H₂O, anhydrous α-, β-, ε-, and γ-CL-20 crystals have been investigated by means of variable-temperature X-ray powder diffraction (XRD) together with Rietveld refinement. The results show that hexanitrohexaazaisowurtane (CL-20) with four polymorphs exhibits linear thermal expansion. The ε phase performs approximately isotropic expansion in the temperature range of 30 to 130°C, but α, β, and γ phases exhibit anisotropic expansion in the temperature ranges of 30 to 130°C, 30 to 120°C, and 30 to 180°C, respectively. The different expansion behaviors are due to the different structures of the four polymorphs. The different thermal expansion behaviors of α-CL-20 · 1/2H₂O and anhydrous α are revealed in this work. The a-axis expansion of α-CL-20 · 1/2H₂O exhibits a switch from positive thermal expansion (PTE) to negative thermal expansion (NTE) at 90°C, whereas the a-axis of anhydrous α is resilient to PTE. The cause is the loss of the structural water. Moreover, it is easily found that the b-axis of the γ phase shows a constriction that may be attributed to the distortion of the six-membered ring.     

低孔隙度低渗透率泥质砂岩储层中胶结指数m和饱和度指数n的计算和应用

低孔隙度低渗透率储层的孔隙结构复杂,连通性较差,孔隙中流体分布不均匀,Archie公式中系数m、n的确定存在较大误差.由传统统计分析方法求取的m和n参数会随孔隙度和含水饱和度的不同变化,使测井电阻率计算的含油气饱和度精度降低.从数学物理边界条件和低孔隙度低渗透率储层的地质特征出发,分析了低孔隙度低渗透率储层中胶结指数m和饱和度指数n的变化特征.从储层岩石的地质作用和岩石物理变化过程探讨低孔隙度低渗透率储层中地层胶结指数m随孔隙度变化的一般规律,并用渗滤门限理论(PPTT)解释这一变化过程,建立了地层胶结指数m和饱和度指数n的准确计算方法.应用新参数对应的饱和度关系对QL油田不同水淹程度的2口井进行了处理解释,获得了良好的效果.     

双螺杆泵的热网络分析

为防止螺杆转子啮合热态间隙不等于设计间隙,有必要对螺杆泵系统进行温度场和热分析研究,而准确地给出热边界条件是开展这一工作的基础。鉴于此,以同步式双螺杆泵为研究对象,用热网络法建立了该部件的热平衡方程组及热阻、功率损失、对流换热系数计算模型,计算了该部件在原油润滑条件下的边界温度,综合考虑了各工况参数对泵温升的影响。     

Prediction of Thermal Conductivity Effects on in-situ Combustion Experiments

Abstract

In this work a mathematical model for a combustion tube was developed. The model takes into account: (a) the heat transfer ahead and behind the combustion front, (b) the combustion zone thickness, (c) the heat generated and lost in the combustion front, and (d) the variation of thermal conductivity with temperature. The predicted combustion front temperature and temperature profiles are in good agreement with experimental data for heavy oils reported in literature. After validation of the mathematical model, further investigations of the effects of thermal conductivity on the temperature profiles ahead and behind the combustion front were studied. Expressions proposed in literature for effective thermal conductivity were used. It was found that: (a) when the functionality of thermal conductivity with temperature is taken into account, the predicted lost heat is different from that using constant thermal conductivity and (b) temperature profiles are affected principally at the beginning and at the end of the tube. The porosity effects on temperature profiles were also studied. In this case, the temperature profiles ahead and behind the combustion front and the combustion front temperature are smaller as the porosity becomes smaller.     

基于岩电参数和颗粒直径的渗透率模型在低孔隙度低渗透率储层中的应用

基于RGPZ渗透率模型分析了岩石中电流导通性能、孔隙结构连通性和渗透率之间的相互关系,并用低孔隙度低渗透率储层的实际测井数据估算的颗粒直径和岩心岩电分析数据预测渗透率。在RGPZ渗透率计算模型中,考虑了反映岩石电流导通特性的地层因素F和表征孔隙结构弯曲度的胶结指数m,以及岩石颗粒直径,三者均可由电测井数据和/或实验分析得到。利用前人发表的多类实验数据和鄂尔多斯某探区的3口井实际测井资料验证了RGPZ渗透率计算模型有效性和对低孔隙度低渗透率储层的适应性,验证结果表明RGPZ渗透率计算模型预测的渗透率在没有微裂缝井段与实测渗透率吻合较好,但在微裂缝发育层段,需要考虑微裂缝对岩电参数的影响。     

稠油热采闭式热流体循环井筒温度场分析

针对"两高"油田原油流动性差的特点以及闭式热流体循环降粘工艺的复杂性,建立了3种闭式热流体循环井筒传热模型及其边界条件,并采用Matlab编写了相应的模型求解程序。通过对现场具体井眼进行模拟计算,对比分析了3种闭式热流体循环效果,给出了最优热流体循环方案。计算了循环流量、循环介质和管柱材料物性参数等对井筒加热效果的影响。计算结果表明,两侧加热方案最好,随着循环流量的增加井筒温度不断升高,导热油作为循环热载体较好,导热性能差的管柱材料能够提高循环加热段产液流动的平均温度。     

岩石热开裂影响因素分析

室内大量岩心的实验结果表明，岩心经过高温热处理后，其渗透率、孔隙度等参数会发生较大的变化且这些变化存在一定的温度界限，不同类型的岩心具有不同的温度界限。从这些实验结果出发，对影响岩石热开裂的因素进行了初步的探讨和分析。     

基于变岩电Pickett图版低孔隙度低渗透率储层流体评价

从低孔隙度低渗透率储层的岩电、压汞实验出发,提出以孔隙结构控制储层导电性为基础,利用储层品质因子计算变岩电参数的高精度模型,结合储层品质特征,改进并建立变岩电参数的Pickett图版,在数值模拟的基础上,给出了变岩电Pickett图版建立的物理意义,并对比分析了固定岩电参数与变岩电参数Pickett图版、不同储层类型的Pickett图版异同点,明确了低孔隙度低渗透率储层饱和度计算误差主控成因及渤海湾盆地中深层出现的高电阻率水层的导电机理,在实际测井资料定性及半定量解释中显示了较好的效果,为油田的低孔隙度低渗透率储层勘探开发提供可靠的参数及流体性质评价方法。     

低热膨胀聚酰亚胺的制备及应用

介绍了四种典型的制备低热膨胀聚酰亚胺的方法,它们是共聚物掺混、多元共聚、添加填料或其他化合物及有机氧烷改性。综述了低热膨胀率聚酰亚胺在微电子技术、柔性印刷电路板等方面的应用。     

超声波对重油热反应的影响

探索了超声波对重油热反应的影响。讨论了超声波作用对重油的粘度、残炭和沥青质含量的影响，并探讨了其作用机理。结果表明，超声波作用大大增加了重油热反应的反应动力。随着超声波作用时间的增加，降粘率增大，残炭值升高，沥青质含量下降，表明油样发生了裂化和缩合反应。作用时间小于1h，油样性质变化较快；1h后变化较慢。超声波对不同油样的热反应影响效果不同。     

海洋石油高孔高渗油田开发储层保护研究

海洋石油开发是一个高风险、高投入的行业,在勘探、开发过程中因工作液使用不当等因素引起的油田储层损害会造成巨大损失。高孔高渗油田由于其自身的特点更容易受到伤害,做好储层保护的研究工作极其重要。对海洋石油高孔高渗油田钻完井过程中油气层保护技术的研究思路、技术要点等问题进行探讨。     

安棚地区特低孔渗油气藏压裂技术优化及应用

针对安棚地区特低孔特低渗且天然裂缝分布不均一的油藏地质特点,进行了岩石物理力学性质及地应力特征研究,优化了水力裂缝和压裂液体系,优选了支撑剂,优化后的支撑半缝长为110－150m,优越出羟丙基胍胶＋有机硼交联剂＋胶囊破胶剂等低伤害压裂液体及高密高强或低密中强的陶粒支撑剂,现场实施后,泌252井日产油提高21倍多,泌253井日产气提高近92倍,取得了较好的增产效果。     

地面直读式电子压力计在稠油热采中的应用

利用高精度、高分辨率的常规地面直读式电子压力计，在汽驱注汽井停注期间和吞吐井抽油阶段测量井温，替代直接吸汽剖面测井，指导稠油开发，启迪从事稠油热采的同行挖掘现有常规试井、测井仪器的潜力，提高热采油藏动态监测的社会、经济效益。     

孤岛油田稠油热化学驱性能研究

利用多种化学剂评价手段筛选出性能优良的热化学剂及高温泡沫剂,并利用多功能泡沫驱油流程研究了不同温度下稠油的热水驱、化学剂及泡沫驱油性能,并对试验结果进行性能对比.结果表明,温度对稠油粘度及采收率影响至关重要,随着温度升高,原油粘度降低,采收率提高.油水界面张力低的热化学驱油体系由于降低了主流线上的残余油饱和度,强化了截...     

多元热流体吞吐技术在海洋稠油探井测试中的应用

稠油粘度大、流动性差,测试作业难度大。以传统蒸汽吞吐作业为基础,在原有的单项注入蒸汽(或热水)的基础上,增加降粘剂、解堵剂、防膨剂、加热设备燃烧柴油产生的气体、氮气等。现场作业表明,多元热流体吞吐技术适合海洋领域稠油探井测试作业。通过该技术,海洋稠油探井产油量、流温增加明显,原油能够增温降粘,加强了原油的流动性。     

Effects of Thermal and Shear History on the Viscoelasticity of Daqing Crude Oil

The relationship between the viscoelasticity and thermal and shear history of waxy crude is important for the safety analysis of waxy crude pipeline operation. A series of oscillatory shear experiments were performed to test the viscoelastic parameters of Daqing crude oil with a controlled-stress rheometer RSH150. The results indicate that the storage modulus and loss modulus increase in an exponential fashion with decreasing testing temperature. There exists a worst heating temperature for the rheological behavior. The strength of waxy structure and gelation temperature increase as the cooling rate is reduced. The shear action is characterized by energy dissipation due to viscous flow. At the same shear temperature, the strength of waxy structure decreases rapidly and finally attains a stable state as the energy dissipation due to viscous flow is increased. Keeping the same energy dissipation due to viscous flow, the closer the shear temperature is to the test temperature, the lower storage modulus, loss modulus, and gelation temperature would emerge. When being close to or higher than the abnormal point, the shear temperature has few influences on the viscoelasticity. The recovery of waxy structure after shear action exhibits an irreversible property.