Advanced Materials Research Vols. 524-527

Abstract: The Karamay Atmospheric Residue (KLAR) was hydrocracked with catalysts in a batch autoclave. The reaction product was separated into IBP-180 oC (gasoline), 180-350 oC (AGO), 350-500oC (VGO) and 500oC+ (cracked residue). The SARA (saturates, aromatics, resins and asphaltenes) separation method was adopted to analysis cracked residue. Then acid number in each fraction was determined. The result shows that: There were about 75% (mass fraction) acid oxygen compounds in the slurry-bed hydrocracking AGO, and were 12%-22% in their cracked residue. In the slurry-bed hydrocracking cracked residue, most acidic oxygen compounds concentrates in resin.

Abstract: Cold Heavy Oil Production with Sand (CHOPS) is an emerging technology. Field practice and laboratory experiment research show the main mechanism of CHOPS are stable foam oil flow producing the internal driving force and the mass sand inflow forming wormhole network leading to the permeability enhancement. In this paper, we summarize the mathematical models describing the mechanism of CHOPS: foam oil model, wormhole model and comprehensive model. The foam oil models mainly describe the formation, properties and flow of foam oil while the wormhole models describe the wormhole growth, the flow in wormhole and sand production predicting. Finally, we discuss the emphasis and directions of research in the future.

Abstract: The scale formation in the oilfield has been a serious problem during the oil recovery process, which influences the oil recovery efficiency tremendously. The composition and surface morphology of the scale obtained from the oil well of Daqing Oilfield of China was analyzed by XRF, XRD and SEM. The results show that, the main compositions of the scale are crystal CaCO3 and amorphous SiO2. Different organic and inorganic acid was used in the scale removal experiments. It’s the inorganic acid that takes the most important part in the scale removal process.

Abstract: The feasibility of methyl-ethyl-ketone (MEK) and N-formylmorpholine (NFM) as combination solvent for separation of butanes and butylenes by extractive distillation was investigated. Based on the thermodynamic studies and laboratory data, five butylenes-enriching plants of 30,000 t/a scale were established. The concentration of butylenes product were 97% (wt%), and the recovery of butylenes achieved was 90%. Antifoam agent was employed to prevent the solvent from foaming and worked effectively. As compared with NFM/MOR (morpholine) solvent system or DMF, MEK/NFM solvent system showed advantages such as low bottom temperature of strip column and low toxicity. Further comparison with ACN (acetonitrile) solvent system indicates that MEK/NFM system presented low residue in top production.

Abstract: Multiphase transportation of the wellhead product in a single pipeline is widely used in oilfields. The oil samples transported in the multiphase pipeline are often live oils saturated by light alkanes. To support the multiphase pipelining more efficiently, in this paper, the solubility and rheology of Chang10 live crude oils are studied at the pressures range from 0 to 2.0 MPa. It was found that the dissolved gas in the live oils is mainly composed of methane (32.70 vol% at 1MPa), ethane (19.43 vol% at 1MPa), propane (21.42 vol% at 1MPa) and C4+ component (22.50 vol% at 1 MPa). The gas-oil ratio, Rs, of the live oils increases rapidly with the increase of saturation pressure. However, the effect of saturation temperature on Rs is very small. The pour point, abnormal point, WAT, viscosity/equilibrium viscosity and yield stress of the live oils decrease obviously with the increase of saturation pressure, meaning that the rheological properties of the live oils improve greatly by gas dissolving. The rheological properties of the live oils are improved mainly by the dilution effect of the dissolved gas.

Abstract: The effects of feedstock’s properties on the propylene yield of catalytic cracking were investigated in a fluid catalytic cracking (FCC) pilot scale riser test unit operating with a circulating catalyst. Under simulated conditions, the results of catalytic cracking with four different gas oils (including two kinds of vacuum gas oil (VGO) and two kinds of coker gas oil (CGO)) show that the yield of propylene is increasing with the ascending hydrogen content of feed. When the hydrogen content is almost the same, propylene yield fed with paraffinic-base VGO is higher than that fed with intermediate-base or naphthenic-base VGO. The lowest yield is fed with CGO because of the more nitrogen compounds, which can poison the acid sites of the zeolitic catalyst.

Abstract: This paper is about the study on desanding technology based on the characteristics of the produced fluid and the principle of the suspension gravity settling. Proposed a new type of three-phase separator by analyzing the species of gravity desanding and the main influencing factors of sedimentation (including particle properties, liquid properties, solid-liquid ratio, containers and stir) .The inclined plane is substituted by a plane on the internal components of the container, which makes the sand deposits easily and then removed by desander. The design principle of the desander is based on the principle of jetting pump (the desanding technology in airtight container). It has been applied to oil filed successfully and provides a reference for further study.

Abstract: Nowadays, most oil fields of China have been developed at their later stage. Water rate of produced oil is very high, and there is great energy loss during the process of management, transportation and storage. In the oil and gas gathering and transportation systems, oil gathering stations account for much of energy consumption. Scientific and effectively analyzing or predicting the gathering stations energy consumption, can reduce the energy consumption of the gathering stations consumption, bring greater economic benefits for the enterprise, and make more important practical significance to society. The process energy analysis of the Chun Liang gathering station is done applying of the “three links” approach. The energy consumption weakness of the gathering station is found applying the “three links”. Corrective measures for the energy consumption are recommended. The recovery of profit is about ￥4.24 million.

Abstract: Interfacial tensions between the weak alkali ternary system with surfactant SHSA-HN6 and Henan crude oil were measured. The effects of adding Na₂CO₃ and Na₂CO₃ concentration, SHSA-HN6 and polymer concentration on interfacial tensions were examined. The results showed that the interfacial tension reduction effect of the weak alkali ternary system was better than that of the alkali-free binary system, and the ultra-low interfacial tension （10^-3 mN/m order of magnitude）for weak alkali ternary system could be reached more rapidly; the influence of polymer concentration changes on static interfacial tension of the weak alkali ternary system was small and the higher the polymer concentration was，the longer the time to reach ultra-low interfacial tension was; the interfacial tension can still be ultra-low when concentration of every component was reduced simultaneously in the weak alkali ternary system; adding Na₂CO₃ not only can reduce the interfacial tension and but also plays a role of sacrificial agent.

Abstract: A method of preparing precured resin coated sand particles was developed. The effects of resins dosages, plasticizer and coupling agent on the sphericity, roundness, crush resistance and flow conductivity of pre-cured resin coated sand were also discussed. Compared with raw sand, the sphericity and roundness of this resin coated sand particles is higher. It also possessed excellent properties to company sample, such as better resistance to crushing, as well as higher short term flow conductivity. By use of the resin coated sand, the cost could be reduced, and the yield of raw oil will be increased. It is a promising method of modified sand in field of hydraulic fracturing treatment.