| Chinese oil field in the early period waterflooding, and most of all into the high water cut stage. How to improve the water flooding recovery in these fields, especially to improve the boundaries of the thick oil-storey water content of the water flooding recovery policy, the urgent and practical significance.Water flooding oil recovery depends on the macroscopic sweep efficiency of injected water and microscopic oil displacement efficiency, and therefore one of the main ways to improve waterflood development is to improve sweep efficiency. The principle is that by changing the underground pressure field distribution of the injected wave and high oil saturation region, in order to drive out the remaining oil in crude oil. Subdivision layer commonly used method to optimize the well pattern and layout, adjusting the injection and production systems, strong note mining, and adjust the injection profile, the water shutoff technology, reservoir deep fluid divert. These methods can significantly reduce water and oil, improve oil recovery.But different from the common reservoir at high water content, high degree of development of the late recovery by sedimentary rhythm, the impact of interference between the layer thick reservoir is easy to form the layer between sudden underground flooding situation is very serious, the potential distribution of remaining oil complexpattern adjustment is carried out under the residual nature of the variation of geological reserves, enhanced oil recovery, are facing technical problems:①The remaining mobile oil potential to accurately predict the three-dimensional quantitative fine description;②The high moisture content of the remaining oil potentialdistribution thin, scattered distribution, small size, reservoir properties, flooding low energy ", and then the use of encryption, strata subdivision and other traditional pattern adjustment techniques to exploit this part of the potential economic benefits will be worse, you need toto study the appropriate boundaries of the stimulation technique, cost-effective comprehensive adjustment of the well network.The average effective thickness of Zhaowa oilfield H3IV2layer is greater than10m, the thickness of the thickest parts is greater than40m, belongs to the massive thick oil layer, the layer of geological reserves accounted for about56%of the Zhao Draw Anpeng District reserves. Has been the main production level since1986to invest in developing, but has experienced24years of development, reservoir thickness, the vertical heterogeneity of serious flooding large differences in the use of non-uniform, the contradiction is more prominent in the layer, the current miningAlthough a degree of only22.67%but the moisture content has been as high as 96.9%, a high water cut development phase. Improve area water flooding recovery in oilfield reserve resources is a serious shortage of background research related to water flooding technology policy limits, to further tap the oil field of the existing resource potential, increase reserves the use of the degree is imperative.On the basis of the fine geological modeling by ECLIPSE black oil model, and combined with the traditional theory of reservoir engineering methods and principles of economics, layer H3IV2pressure system technology boundaries, injection and system technology boundaries, the measures of the technical limits of the yieldpattem adjustment technology boundaries demonstrated. Finally, Proposed the enchanced water flooding recovery program by the vector well theory and the results of economic and technical limits. The specific contents are as follows:1、Reservoir engineering, combined with industry to develop evaluation criteria, the rate of increase in yield, moisture content variation, and the storage rate, water rate, water, water content and degree of recovery, injected into a multiple of the growth rate, production of liquid absorbent, the formation pressureother development indicators of the development effect of H3IV2and facing the need to improve the problem, pointing out the direction for improving water flooding effect.2、Use a variety of methods to study the policy limits well density and well spacing. Including:oil production rate, water injection capacity analysis, the liquid discharge capacity analysis, numerical simulation analysis methods from the aspects analyzed the impact of various factors on the well network, and well spacing. And draw the plates under different oil price and development costs, and provides a reference for the late pattern adjustment.3、Single well of the economic limit production, control the reserves boundaries of study. Average daily oil production from a single well the economic limit, the single well control the recoverable reserves, the geological reserves of the economic limit under different oil oil-producing economic evaluation. Provides a cost-effective to adjust well network evaluation criteria and boundaries.4、Reasonable formation pressure to maintain the level boundaries. The material balance method, the method of static water pressure, formation pressure and accumulation of injection-production ratio Relations Act, the development of the effect to determine the reasonable formation pressure to determine a reasonable level of formation pressure boundaries, provides a basis for post-injection and adjustment.5、Reasonable injection wells ratio boundaries. Use the absorption Aquatic fluid index method, suction Aquatic fluid index and injection method, the relative permeability curves method, suction the Fisheries fluid index than the injection and differential pressure method to determine the boundaries of reasonable injection-production ratio for post-injection and structural adjustment basis.6、Reasonable injection. Using formation pressure and the injection-production ratio, the material balance equation method to determine a reasonable injection to obtain a reasonable injection than boundaries, provides a basis for the adjustment of the late.7、Fluid production, oil production rate and the limits of research. Balanced injection was studied by different well density, the injection strength, reasonable oil production rate under different moisture content. Numerical simulation to determine a reasonable speed of fluid production. Provides a reference for the development of rational production system.8、Layer interference boundaries. Select AN78typical well group, the use of numerical simulation technology, and steps from the pressure and permeability are two main factors of pressure, the permeability ratio of the impact of interference between the layer boundaries, provides a reference for a combination of strata.9、The remaining oil distribution summary and classification of the evaluation. Combination of reservoir engineering, sedimentary facies, flow units and numerical simulation results on the distribution of residual oil and shunt formula have been classified in the remaining oil, and pointed out the direction for the latter part of the program adjustments.10、Vector well theory and its application in the H3IV2block. Combined with the theory of vector well, and numerical simulation of the theory to block the use of H3IV2argument.11、Reservoir injection and structural adjustment programs and the indicators forecast. The combination of the above analysis, to develop a H3IV2adjustment programs, and from an economic point of view, the preferred argument of the modulus.Forecasting and economic evaluation of the program targets, the program is feasible. The preparation of the program not only play an active role in oil field Zhaowa three sections IV2layer and improve performance, improve recovery, and perfect adjustment of the old oil field development of post-injection patterns, especially thick layer of reservoir development of guiding significance. |
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