Advanced Materials Research Vols. 361-363

Abstract: Polymer solution is known as non-Newtonian Fluid. Hence, when a well is injected by polymer solution, the well test data analysis using Newtonian fluid flow model will be erroneous. However, the analysis results usually were inaccurate when generalized non-Newtonian fluid model which considering polymer solution as power law fluid and taking no account of physical and chemical behaviors. These results clearly suggest the need for a study to come up with a new model considering both physical and chemical behaviors when polymer solution flowing in the reservoirs. At first, this study modified two parameter models: viscosity model and permeability decreasing coefficient model, all of them considering diffusion, conduction and IPV (inaccessible pore volume). Then, those models were applied to set up the new well testing model of a well located in an infinite reservoir. The log-log plots of the pressure and pressure derivatives have been prepared through numerical solutions. A further study has been done about the characteristics of the new type curves considering different parameters.

Abstract: This paper introduces the Grey theory to evaluate the injection-production well connectedness in polymer flooding reservoir. Gery theory can give the law of the data by data analysis and calculation. Through the production data dynamic analysis and calculation using the Grey method, realized the injection-production well connectedness quantitative evaluation in polymer flooding reservoir. Comparing the injection-production well connectedness calculate by the Gery method with the tracer test result shows that using the Gery method to calculate the injection- production well connectedness can get reliable and accurate results. This method can be used to calculate the injection-production well connectedness in polymer flooding reservoir.

Abstract: Particle Impact Drilling technology (PID) is a new drilling technology, which is designed especially to solve the oil and gas exploration under hard terrane. In PID system, the steel particles were added in the drilling fluid to impact rock. The particles would be recycled and put to use again, thus it is of great significance to adjust proper drilling fluid flow rate for steel particle’s reflux. The flow rate of drilling fluids carrying particles is influenced by the fluid viscosity, the annular gap between drill pipe and wellbore, the particle volume fraction and particle size, etc. This paper mainly studied the influence of the annular gap and the flow rate, while the other factors keep constant. Both experimental method and dimension theory were employed in the research. Furthermore, empirical formula was proposed to describe the mechanism.

Abstract: Drilling is one of the major means for oil and gas exploration and development. Extended reach wells (ERWs) are defined as directional wells or horizontal wells with horizontal displacement (HD) to vertical depth (VD) ratio greater than or equal to 2. Extended reach drilling (ERD) confronted many technical difficulties. Risk analysis of ERD before drilling is of great significance for preventing complex accidents during drilling operations, improving the drilling rate and efficiency. Based on gray matter-element theory, this paper established a comprehensive risk assessment model for ERD operations and applied this model to evaluate the drilling risk of Well B6ERW07(HD to VD ratio 5.94, horizontal displacement 7,419.42 m, vertical depth 1,248.50 m, measured depth 8,144.31 m)in the Liuhua oil field, South China Sea. The assessment results show that the predicted success rate of drilling this ERW is 49.9%. This result can be important criteria and thus contributes greatly to decision making.

Abstract: In order to probe a new enhanced oil recovery technology during the post polymer flooding process, we constructed the 16SrDNA gene library and analysed PCR-DGGE during the post-microbial enhanced oil recovery of polymer flooding process. Through the research for the reservoir system, we studied the microbial community structure and genetic diversity after polymer flooding process, made the phylogenetic analysis. It is supposed to provide a dependable basis for MEOR through directional control microbial community of reservoir, through development and application of effective microbial flooding technology.

Abstract: With complicated geological background, Putaohua reservoir in Sanzhao depression has lots of blocks. Based on its distribution characteristics and evaluation unit division as well as combined with detailed geological characteristics, parameters of developed and undeveloped blocks were optimized and the comprehensive evaluation parameters were determined. In order to make a correct evaluation for oil content, oil distribution, reservoir physical properties and productivity, this paper has adopted comprehensive quantitative evaluation method to do the comprehensive classification and evaluation for developed and undeveloped blocks. It can not only further improve oil recovery of developed blocks but also provide scientific basis for selecting favorable blocks for productivity construction of undeveloped blocks. According to the classification standard, the developed and undeveloped blocks of Putaohua reservoir in Sanzhao depression were separately divided into three types including Class Ⅰ, Ⅱand Ⅲ. In view of the geology and development factors, undeveloped blocks of Class Ⅰ are equivalent to developed blocks of Class Ⅱ; undeveloped blocks of Class Ⅱ are equivalent to developed blocks of Class Ⅲ; undeveloped blocks of Class Ⅲ are the poorest of all.

Abstract: Micro pore throat characteristics of extra low permeability sandstone oil reservoir of Yangchang group in Ordos basin are analyzed using constant rate mercury penetration technique. The results show that pore radius distributes similarly, in 100～200μm, peak values are about 140μm in extra low permeability sandstone oil reservoir. The lower the permeability is, the narrower the distribution ranges of throat are, content of smaller throats become high and variation is more sensitive to permeability, distribution ranges of pore throat radius ratio are wide and permeability has bigger influence on input mercury saturation of throat in extra low permeability sandstone oil reservoir. The difference of pore throat characteristics mainly depends on throat in extra low permeability sandstone oil reservoir. The impacts of pore and throat on total capillary curve are various to different permeability cores, Throat development should be paid more attention in middle or later stage of oil development to extra low permeability sandstone oil reservoir.

Abstract: In order to reduce the temperature of paraffin-based crude oil，is applied low-temperature dehydration performance of the AE8051, is the good effects of high viscosity crude oil dehydration polyether polyol-based SAA and polyoxyethylene polyoxypropylene glycol ether BP28 for "coordination" recovery distribution is also applied. As result , a small amount of C-F surfactant will make the system active and increase the solubility of paraffin-based demulsifier in crude oil at low temperature FYR-015. The basic formula, which by low-temperature synthesis of a series of demulsifier samples at concentration of 200mg / L(in water) and 30% of the joint stand of the mixed oil at 40 °C, has been the relative dehydration rates of 90 minutes over 93% of the 3 a formula of low-temperature demulsifier, the dual temperature demulsifier compound obtained in the same temperature, the same dosage effect of the case of dehydration and a single dose equivalent in dosage trials are three formulations of low temperature demulsifier in 40 °C are the best dosage 100mg / L. Xuanze solid content of 55% of finished emulsion breaker formulation 5 into field use, dosage to 60 mg / L when the water content of crude oil were isolated less than 0.2%, to reach the standard of foreign crude oil output quality, extrusion sewage oil is less than 50 mg / L, water clear.

Abstract: Profile control/water plugging is an important approach to increase production. Reasonable treatment radius and the volume of blocking agent are essential parameters not only in profile control/water plugging engineering but also in the area of reservoir simulation. Traditional calculation method used for treating layer only is derived by Darcy's equation. However, traditional calculation method neglect the influence of multilayer characteristics, which may lead to erroneous results. In this research, a new calculation method about profile control/water plugging is derived by considering the influence of multilayer characteristics. In order to derive this equation, layered-parallel beds model is established and ideal Darcy's radial flow theory is applied. In the new calculation method, treatment radius depends on desired effects, water plugging effect and multilayer characteristics. The scheme proposed by using the new calculation method is evaluated by using data from block SH2 in the HeNan oilfield. Calculation results show that the variation of treatment radius is generally in good agreement with actual situation.Introduction.

Abstract: High yields and higher efficiency can be acquired by using horizontal well as it has a lager contact area reservoir. So the horizontal well has become a better choice to gas fields all over the world, especially to low permeability oil fields in the world. There are several inflow performance models for horizontal wells. This paper studies several horizontal well models currently widely used in the word through an example of Chinese oil field. These include steady state model of Giger model, Joshi model and Renard and Dupuy model. And pseudo steady model of Babu and Odeh model. The results show that Giger model give greater production rate from our procedure and calculation.