Advanced Materials Research Vols. 1073-1076

Abstract: This paper research the hydrolysis law of BH heat-resistant polymer in distilled water, oil field clear water and oil field waste water, and inspect its long-term thermal stability in the waste water. The results showed that there is few difference about hydrolysis degree between the ZIIordinary polymer and BH heat-resistant polymer in distilled water. BH heat-resistant polymer will hydrolyze faster in the waste water than in the clear water. The hydrolysis degree of different concentrations of BH of polymer solution under the same temperature increases with the increase of aging time, the higher the polymer concentration, the higher the viscosity of the solution, the smaller the hydrolysis degree. BH heat-resistant polymer hydrolysis under high temperature will increase, caused the increase of hydrolysis degree from 95°C to 120°C. AMPS group of BH heat-resistant polymer will not hydrolyze under 95°C.

Abstract: The flow pattern is unique in a certain range of pore size divided by the Knudsen number. In order to characterize permeability of nanopore in shale gas reservoir more accurately, the formulas of nanopore permeability are put forward considering the influence of adsorption gas and flow patterns. After the calculated results were compared and analyzed, the conclusions are obtained as follows: (1) Pore size is the main factor to determine the flow pattern; (2) There are three main flow pattern in the nanopore of Longmaxi formation shale reservoirs, slip flow, Fick diffusion and transition diffusion, meanwhile Darcy percolation and Knudsen diffusion do not exist; (3) Flow pattern has great influence on apparent permeability and adsorption has a greater impact in a high pressure condition (greater than 20MPa).

Abstract: Due to the common problems of waterflood in low-permeability reservoirs, the reasearch of finely layered water injection is carried out. This paper established the finely layered water injection standard in low-permeability reservoirs and analysed the sensitivity of engineering parameters as well as evaluated the effect of the finely layered water injection standard in Block A with the semi-quantitative to quantitative method. The results show that: according to the finely layered water injection standard, it can be divided into three types: layered water injection between the layers, layered water injection in inner layer, layered water injection between fracture segment and no-fracture segment. Under the guidance of the standard, it sloved the problem of uneven absorption profile in Block A in some degree and could improve the oil recovery by 3.5%. The sensitivity analysis shows that good performance of finely layered water injection in Block A requires the reservoir permeability ratio should be less than 10, the perforation thickness should not exceed 10 m, the amount of layered injection layers should be less than 3, the surface injection pressure should be below 14 MPa and the injection rate shuold be controlled at about 35 m³/d.

Abstract: This article revises the low pressure reservoir Block 5 controlled by structure trap located in South China Sea and analyses the current situations of the reservoir including G&G and reservoir engineering. The results indicate that down-dip wells already located in the water which was original oil based on new study and now could be converted to injector to increase oil reserves. Finally according to the study, the same method can be used in the similar reservoirs.

Abstract: The three-dimensional flow-temperature numerical coupling model was established based on the Three-Dimensional Environment Fluid Dynamics Code Model. The reservoir water temperature was simulated coupled flow and water temperature and stratification pattern was analyzed attempting to provide scientific reference for water design and operation management on proposed reservoir, which could slow down the influence of low temperature water of proposed reservoir on ecological environment and aquatic biodiversity of the downstream river. Results show that reservoir water temperature stratification pattern distinguishes obviously among low temperature period, rising temperature period, high temperature period and cooling period and the temperature hysteresis effect is remarkable. The drainage of low-temperature water in summer should be prevented from influencing downstream ecological environment and the mechanism of the impact of high-temperature water in winter on ecological environment needs further study.

Abstract: According to the high resolution sequence stratigraphy’s theory^[1] and the information of rock-mineral analysis, geophysics data, biological stratigraphy and geochemistry, this paper made a systematical and in-depth research on sequence boundary identification marks of Gaotaizi reservoir of Qijia area in songliao basin. We use core identification, logging curve, paleontology, heavy mineral analysis and seismic prospecting data to explain how to find the sequence boundary. And there are two types of boundary were recognised on G3,G4 oil layer group of Qijia area, which are used to be the basis to make G3,G4 into 5 parts, one is the transition surface of deltaic plain and shallow lake, the other is the top of ascending order of delta front.

Abstract: Oil-gas migration is an important process of the reservoir formation. Based on this discussion, a numerical simulation was conducted to study on oil-gas migration and aggregation. With considering the flow behavior of gas-liquid two-phase flow, based on Navier-Stocks equations and the Darcy’s law, the movement characteristics of natural gas within the typical fault passage are predicted by using the finite volume method and pressure-velocity coupled algorithm. The velocity distribution of natural gas is discussed under the primary migration condition, as well as the diffusion concentration at different locations. Moreover, the position of spill points affecting natural gas aggregation is analyzed, which provides a theoretical basis for predicting reservoir formation and transport processes.

Abstract: Air foam flooding is an important means in tertiary oil recovery. As of July 2013, in the case of low recovery degree, Da Gang oilfield has entered high water cut period, thus increasing of recovery is under pressure. This experiment simulated the actual reservoir temperature and pressure, through the establishment of physical model, implemented a series of contrast tests, systematically evaluated four variable parameters, including gas liquid ratio, injection mode, permeability, and injection speed. Experimental results has cleared the effect of variable parameters on air foam flooding, so as to provide guidance for oilfield production.

Abstract: Fault block reservoir in Shengli Oil Field has been developed by the “top intense, edges disperse” method. Although it can receive good development efficiency, the mechanisms and regularities are not very clear, need to be identified. In this paper, based on the special types and characteristics of Shengli Oil Field, we used real model, conducted a deeper research though reservoirs engineering, and found the fluid flow behaviors, the main controlling factors and microscopic distribution. The effects of gravity, capillary force and patching holes were also analyzed. The results show that reservoirs with effective edge and/or bottom water would have better development efficiency.

Abstract: Three dimensional (3D) geologic modeling is used to study the reservoir quantitatively from a three-dimensional angle, and its core is the prediction to reservoir of multi-disciplinary integration, quantitative and visualization. Compared with traditional reservoir research, it has a significant advantage. This paper makes geological modeling research and builds structural models sedimentary micro-facies models and phased property model for Hei46 block of Daqingzi oilfield by utilizing 3D geologic modeling technique and petrel software on the basis of integrated using of geology, logging, oil production test, production of dynamic information, thus it provide a reliable basis for reservoir's development and adjustment.