Study Of Comprehensive Design For Profile Modification Program At Bei301 Block Of Hailaer Oilfield

Reservoir heterogeneity is a widespread existence which makes the water intake profile not uniform to cause reduction of the vertical sweep efficiency of the water injection. Hence the water channeling is formed by this injected water. And due to the act of long contact and flush between the injected water and the rock particles and skeleton, the high permeable band becomes larger and larger to form the high permeable path which might reduce the efficiency of the injected water to a great extent. Then the water cut of oil wells would increase swiftly. While the water production of a oil well is the comprehensive results of several water injection wells, water plugging and profile adjustment should be considered according to all the block.Based on the perfection and the accuracy, the decision-making techniques were designed for two blocks such as the fuzzy comprehensive evaluation and the numerical simulation. Taking advantage of physical simulation,we developed a new profile control system and gave a comprehensive evaluation for its performance.By the mutual verification and their complementation, a mathematical model was built on the program optimization for block profile adjustment and water plugging.On the bases of the original studies, a large number of reservoir engineering parameters were used completely, such as in the injection wells the apparent water injectivity index, water injectivity index, pressure drop curve, permeability heterogeneity, water intake profile heterogeneity, and in the oil wells the total liquid production, average water cut, residual reserve of the linked oil wells and the degree of recovery. After selection of the three primary factors indicating the water intake capacity of water wells, the heterogeneity of oil layers and the related dynamic status of the around oil wells, Calculate all the the decision-making factors, according to the results of multi-level decision to calculate the final decision-making factor FZ, according to its size as a option profile control wells conditions to whole block, while further study is optimized for transferring profile control layer of fuzzy comprehensive evaluation decision-making techniques. And an example calculation of the profile control wells: profile control radius, profile-modifying agent dosage, profile-modifying agent injection pressure and injection rate during the construction .With the established numerical simulation simulations also considered the closure rate, profile control radius, profile control timing, heterogeneity and inter-layer crossflow swap profile control effect.The results from both the fussy comprehensive evaluation and the numerical simulation show that at the block 301 of Halar Basin the reasonable profile adjustment radius is about 3m, the aim formation temperature was among the range of 45～60℃, the effective thickness of the sublayers was among the range of 0.3～24.3m. At the same time, based on the weak gel of PAM-monophenol, a profile adjustment system with high strength and quick crosslink capacity was designed and optimized including the PAM and the mixed phenols (monophenol and multiphenol). This new system has the gel strength about 105 mPa·s and gelling time within the range of 1～5d. Other studies such as the field application environment effects (formation water, pH value and the temperature) on the gelling time and strength, the comprehensive performance, the resistance to shearing, the breakthrough pressure, the resistance to flushing were also make. Finally, the degree of recovery was evaluated for the new system on a man-made rock sample with the variation coefficient of 0.5.Taking use of numerical simulation techniques,we established a three-dimensional geological model with petrel software for Bei301 blocks,made waterflood history match and remaining oil distribution with eclipse software. The history matching resulted that:the relative error of fitting results on oil production was less than 3.1%,and the relative error of fitting results on cumulative oil production was less than 1%. On this basis,with the established numerical simulation simulations also considered profile control effect of the plugging rate, profile control radius, profile control timing, heterogeneity and inter-layer crossflow.The result showed that: for Bei301 blocks,when 40～90% of the moisture content of production wells was the profile control timing, profile control radius was 3m, the plugging rate was 80～90%, the increase degree of recovery was maximum;the heterogeneity of profile purpose reservoir was higher, the vertical permeability ratio was greater, the increase degree of recovery after the profile was higher;the high layer channeling is not conducive to increase the profile results.Based on the features of the fermation thickness, permeability, wide-scale distribution at Bei301 Block, a new profile control system with the both gelling time and gel strength djustable was developed. And the reaction mechanism and nature of the profile control system in their three stages of addition-condensation process was also described deeply according to the special functions of the condensation compound caused by the change of organic polymer functional groups attributed by energy conversion.