Using a fully coupled flow and geomechanical simulator to model injection into heavy oil reservoirs

In this paper, the geomechanical factors that may affect injection processes in heavy oil recovery are investigated. To accurately capture the geomechanical effects, we employed a numerical formulation that allows fully coupling of nonlinear geomechanical deformation and multicomponent porous media flows. Two salient features of this new coupling formulation are the following: (1) all flow and geomechanical equations are solved implicitly in one single matrix equation, and (2) it allows reuse of matrices from both a traditional fully implicit multicomponent reservoir simulator and a nonlinear geomechanics simulator. The former feature ensures stable coupling between the reservoir flow and geomechanics, and the latter significantly reduces the programming work. Numerical examples are given to demonstrate the accuracy and convergence performance of the new formulation. The proposed formulation is then applied to model injection into heavy oil reservoirs. The numerical investigation revealed that geomechanical factors, such as in situ stress anisotropy and the uneven deformation of reservoir rock and attached impermeable rock, can result in skewed or nonuniform plastic strain and, hence, alter the sweep of the injected fluid. Coupled geomechanics simulation also gives rather different transient pressure response from that of uncoupled simulation. Copyright © 2012 John Wiley & Sons, Ltd.     

基于物联网技术的海上原油过驳智慧监管研究

分析了我国现存监管手段的不足，针对实际监管要求，基于信息化技术的快速发展及物联网技术在其他领域的成功应用，提出海上原油过驳的智慧监管体系的总体构架，并阐述了有关功能，为以后建设基于物联网技术的海上原油过驳智慧监管体系提供了参考。     

Mechanism for viscoelastic emulsion displacing oil film – A numerical simulation approach

The reservoir characteristics and fluid property of Daqing reservoir were taken as the research platform. For simulating the emulsifying process in the reservoir, injecting different concentrations of emulsifier solution into the core after water flooding, the viscoelasticity of the emulsion was measured. According to the value of the emulsion viscoelasticity, the numerical model of emulsion displacing oil film was established. Elastic stress acting on the oil film was calculated when the emulsion migrates. The deformation and transportation of the oil film were analyzed at bearing the elastic stress. The results show that the emulsion has favorable viscoelasticity. When the emulsifier concentration is higher, the emulsion elasticity is favorably increased. The oil film can deform and transport forward by the elastic stress. The elastic stress increases as the emulsion elasticity increases.     

Synthesis, characterization, degradation of biodegradable castor oil based polyesters

A new family of castor oil based biodegradable polyesters was synthesized by catalyst free melt condensation reaction between two different diacids and castor oil with d-mannitol. The polymers synthesized were characterized by NMR spectroscopy, FT-IR and the thermal properties were analysed by DSC. The results of DSC show that the polymer is rubbery in physiological conditions. The contact angle measurement and hydration test results indicate that the surface of the polymer is hydrophilic. The mechanical properties, evaluated in the tensile mode, shows that the polymer has characteristics of a soft material. In vitro degradation of polymer in PBS solution carried out at physiological conditions indicates that the degradation goes to completion within 21 days and it was also found that the rate of degradation can be tuned by varying the curing conditions.     

烧原油高效燃烧器的研究

本文讨论了用于油田加热炉的一种烧原油高效燃烧器的设计，论述了Ｙ型蒸汽雾化喷嘴、正交蒸汽雾化喷嘴和高压离心喷嘴的具体设计结果。该燃烧器对原油加温并采用内、外双漩流器组织燃烧，明显提高了燃烧效率。最后还指出了这种燃烧器的开发与应用前景。     

Monitoring oil displacement processes with k‐t accelerated spin echo SPI

Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time‐dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T₂ signal lifetime distribution. In this work, a pure phase‐encoding MRI technique, spin echo SPI (SE‐SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k‐t acceleration method, with low‐rank matrix completion, was employed to improve the temporal resolution of the SE‐SPI MRI measurements. Comparison to conventional SE‐SPI T₂ mapping measurements revealed that the k‐t accelerated measurement was more sensitive and provided higher‐quality results. It was demonstrated that the k‐t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no ¹H, and H₂O brine were employed to distinguish oil and water phases in model flooding experiments. High‐quality 1D water saturation profiles were acquired from the k‐t accelerated SE‐SPI measurements. Spatially and temporally resolved T₂ distributions were extracted from the profile data. The shift in the ¹H T₂ distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd.     

Application of pyrolysis–mass spectrometry and pyrolysis–gas chromatography–mass spectrometry with electron-ionization or resonance-enhanced-multi-photon ionization for characterization of crude oils

A novel analytical system for gas-chromatographic investigation of complex samples has been developed, that combines the advantages of several analytical principles to enhance the analytical information. Decomposition of high molecular weight structures is achieved by pyrolysis and a high separation capacity due to the chromatographic step provides both an universal as well as a selective and sensitive substance detection. The latter is achieved by simultaneously applying electron ionization quadrupole mass spectrometry (EI-QMS) for structural elucidation and [1 + 1]-resonance-enhanced-multi-photon ionization (REMPI) combined with time-of-flight mass spectrometry (ToFMS). The system has been evaluated and tested with polycyclic aromatic hydrocarbon (PAH) standards. It was applied to crude oil samples for the first time. In such highly complex samples several thousands of compounds are present and the identification especially of low concentrated chemical species such as PAH or their polycyclic aromatic sulfur containing heterocyclic (PASH) derivatives is often difficult. Detection of unalkylated and alkylated PAH together with PASH is considerably enhanced by REMPI–ToFMS, at times revealing aromatic structures which are not observable by EI-QMS due to their low abundance. On the other hand, the databased structure proposals of the EI-QMS analysis are needed to confirm structural information and isomers distinction. The technique allows a complex structure analysis as well as selective assessment of aromatic substances in one measurement. Information about the content of sulfur containing compounds plays a significant role for the increase of efficiency in the processing of petroleum.     

兖州煤与催化裂化油浆共处理及其重质产物组成性质的初步研究

采用石家庄催化裂化油浆和兖州煤共处理，考察了反应条件对兖州煤转化及产物分布的影响，并应用棒状薄层色谱分析了共处理重质产物族组成的变化规律。结果表明，催化裂化油浆与兖州煤共处理，可大大提高兖州煤的转化率，共处理既可得到部分轻质油品，又可得到相当量的重质产物。ＴＬＣ／ＦＩＤ分析表明，催化裂化油浆与兖州煤共处理的重质产物与商用高等级道路沥青族组成近似，重质产物可用于制备高等组道路沥青。     

Modified polysaccharides for use in enhanced oil recovery applications

Aqueous solutions of a charged hydrophobically modified hydroxyethylcellulose (HM-HEC(−)) exhibit high viscosities even at low polymer concentrations (0.2 wt%), which is an interesting feature in connection with enhanced oil recovery. This polymer was synthesized for this work. Effects of temperature and addition of sodium dodecyl sulfate (SDS) or hydroxypropyl-β-cyclodextrin (HP-β-CD) on the viscosity properties of a semidilute solution of HM-HEC(−) are examined. The results for the HM-HEC(−)/SDS system disclose strong interactions between HM-HEC(−) and SDS at low level of SDS addition, and this leads to a significant viscosification of the polymer-surfactant mixture. At higher surfactant concentrations the association complexes are disrupted. A strong temperature effect of the viscosity is observed at moderate levels of SDS addition, with lower values of the viscosity at elevated temperatures because of enhanced polymer chain mobility that breaks up the associations. Addition of HP-β-CD monomers to the HM-HEC(−) solution generates decoupling of associations via inclusion complex formation with the polymer hydrophobic tails and the viscosity decreases. By using temperature and addition of these co-solutes, it is demonstrated that the viscosity of the polymer solution can be tuned over a large range of viscosity values.