Advanced Materials Research Vols. 807-809

Abstract: Considering the pressure-sensitive effect and threshold pressure gradient in low permeability reservoirs, a new mathematical model of the variable permeability for reservoir between injection and production well is established. The Garlerkin method is used to set up the finite element computation equations, and corresponding numerical simulation program is developed. The influence of Injection-production pressure, well spacing and hydraulic fracture are quantitative evaluation. The simulation results show that the pressure-sensitive effect and threshold pressure gradient has a strong influence on pressure distribution between injection and production wells. Establishing the effective driving pressure system is the key to improve well production of low permeability reservoir.

Abstract: The research on volcanic diagenesis have important value in volcanic secondary pore formation, evolution and reservoir prediction. Using core, slice, imaging logging and geochemical analysis, from lithology-lithofacies characteristics of Yingcheng Formation in Xujiaweizi depression, Songliao Basin, study on volcanic diagenesis, types, characteristics and relationship of reservoir space. The results are shown that: The volcanic mainly developed dissolution 13 diagenesis types, and base on the formation mechanism and effect to the reservoir space, it is divided further into constructive and destructive categories In the study area; Reservoir performance of reservoir space depend on the type, combination form and development degree, and the diagenesis is main control factor of rservoir space (pore, crack) formation, preservation, damage evolution characteristics; volcanic diagenetic complexity is the main reason of reservoir space complexity and diversity.

Abstract: The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO₂ .The natural oil sand from Qi 40 block formation is made into 5 teams total 10 high temperature and pressure long double tube reservoir nonhomogeneity models .The experimental oil is simulation oil which is made by mixing the wellhead crude oil with diesel. On the base that steam soaking and steamdriving recovery reach to the current oilfield average level, we do 1 group double tube steam +CO₂ composite displacement experiment and 4 group double tube surfactant adjustable profile + steam +CO₂ composite displacement experiment. And record after steamflooding steam drive with carbon dioxide and surfactant improvement value. The results show that in the steam composite flooding, enhanced oil recovery rate increases as the number of composite plug PV growing. Carbon dioxide and steam are injecter by 1:1 alternately and composite plug is 0.3PV, in which enhanced oil recovery rate can reach 19% and cost of oil displacement agent is 38.77 Yuan/ton of oil. Carbon dioxide and II thermostability discharge aiding agent are injecter by 1:1 alternately and thebest composite slug is 0.3PV, in which enhanced oil recovery rate can reach 23.7% and cost of oil displacement agent is 289.66 Yuan/ton of oil. When the plug PV number is same(0.3), surfactant + CO₂ composite plug can improve more 4.7% than steam +CO₂. Hence, thermostability discharge aiding agent have some effects on improving recovery.

Abstract: Directing at lateral accretion interbed layers, wedge-shape and pinch-out models are used to analysis polymerflooding development effect using Eclipse numerical simulation soft.. And the distribution location of remaining oil is given after waterflooding and polymerflooding.The recovery is provided including two parts which are lateral accretion interbed and non-lateral accretion interbed. Horizontal well and vertical well are united to exploit remaining oil, in which case, the vertical and horizontal positions of horizontal well are optimized.Numerical simulation results indicate that polymerflooding recovery increasement value is respectively 11.47% and 11.34% about wedge-shape and pinch-out models and polymerflooding works well. The closer to top the horizontal well is , the greater recovery enhancement values is for wedge-shape and pinch-out models. Horizontal hole section starts from the location of seven-eighths of lateral sandbody I left and terminats seven-eighths of lateral sandbody IV, where the recovery is highest, which are respectively 6.69% and 5.61%.

Abstract: In order to better protect the Daqing Oilfield Sanan oil field development, make experimental analysis and field applications of Sanan's core.Through the relationship between rheology and fluid loss ,achieve JGN best dosage of the entire completion fluid system, completion rheological law and evaluated regular patten.The effect of field application is obvious, improve strength of the oil production , the skin factor and injection pressure is reduced, and made better protect the reservoir effect.

Abstract: With the continual advancement of oil field development, water cut is an extremely important parameter which determines the transmission characteristics of the oil production and provides a scientific basis for oil and gas optimization exploration and increase of reservoir recovery. A new type of water cut meter based on fiber optic interferometer is proposed, sound pressure signal on the pipe is generated when the acoustic wave is propagated in a mixture of the pipe, the fiber optic sensors wrapped closely around the outside wall of pipe is capable of sensing sound pressure signal, the use of phase carrier technology aloud sound velocity is solved out through the method of Phase Generated Carrier (PGC) and sound pressure spectrum, then water cut can be solved according to the relationship between sound velocity and water cut.

Abstract: In this article, the experimental study on proppant transport performance of GRF-CO₂ system is performed by using the large-scale foam fracturing fluid test system of high temperature and high pressure, and critical settling velocity and proppant settling velocity are obtained.Research results show that the critical settling velocity increases with the temperature rising, in foaming cases,decreases with the foam quality and sand ratio rising.The correlations for GRF-CO₂ fracturing final proppant settling velocity within solution and the critical settling velocity have been obtained, all kinds of average error is less than 14%.

Abstract: The basic situation of associated gas generations (AGGs) in Changqing Oilfield has been introduced in this paper. The conception of power loss contribution degree is used to analyze the power loss under different conditions of AGGs. And the idea of reactive effect rate is proposed to express the relation between AGG and grid, and the causes of insufficient reactive power are given simultaneously. Moreover, the method of reliability-network-equivalent is used to study the reliability evaluation pre and post the AGGs paralleling. The results of calculation indicates that controlling of capacity and installation site, increasing the reactive power and improving the performance of AGGs equipments should be important measures.

Abstract: Oil well casing damage is one of the security problems in petroleum engineering, it should be paid more attention in oil and gas development. Influence factors of oil well casing damage are very complicated, and the evaluation criteria of each influence factors are different. Therefore, for the assessment of casing damage, should be based on a comprehensive engineering and petroleum geology of the argument, using multi-criteria evaluation method to implement from the safety point of view. The development of multi-criteria evaluation method based on GIS oil well casing damaged isnt only consider the relative importance of each influence factor, but also fully consider the various factors of space walks and order of importance. With the help of IDRISI software, Jinzhou oil production plant in the 25 block as an example, calculating order weights and criteria weights, the comprehensive evaluation of damage to the casing pipe of oil well is made. By comparison of weighted linear combination method and the ordered weighted average (OWA) method, analyzes the ordered weighted average method advantage.

Abstract: Oil-based drilling fluids and synthetic based drilling fluids are frequently used in shale-gas plays when wellbore stability is necessary. In this paper, a novel nano-polymer, as a plugging agent in oil-based drilling fluid, was prepared and characterized by Fourier transform infrared (FTIR), thermo-gravimetric analyses (TGA) and scanning electron microscopy (SEM). The rheological properties, high temperature-high pressure (HTHP) filtration properties and permeability plugging properties of oil-based drilling fluids were greatly improved by adding the nano-polymer, due to its nanometer size and the compact layer formed on the surface of the core.