Research On Feasibility Of Well Patterns Thickening In Weixing

Well patterns thickening technology is one of the means of increasing oil production and enhanced oil recovery, and also is one of the measures taken by each oilfield. The Weixing oilfield uses 250~350 meter-well-distance counter-nine areal pattern, and has received effect. But at present, the oil layer grows bad, the coercion of water-flooding was low and the usage of various types of reservoir was poor, so the limited reserves have not been effective used. Under the current development methods, the scale-development areas will enter a stage that the aquifer increased rapidly and the production will decline faster, stabilize of the production will be very difficult and the prediction production will be only about 20%, the result of development is not satisfactory. The main problem is that the current pattern, well spacing does not match the reservoir. One of the reasons is part of the reservoir properties were poor (permeability that less than 20×10-3μm2 accounted for 44.6% of the reservoir), the current well spacing, can not establish an effective drive system, part of the reservoir under the current pattern can not be used effectively; Secondly, development of small-scale sand bodies, the general width is only 100-300m, and the area of 250×250m counter-nine well spacing pattern was not suited, and the ratio of injection-production well was higher and have more faults fault ,the control of water-flooding was low, a number of reservoirs can not used. The best time to Injection-production system encryption and adjust was the moisture content generally in the 40-60%, and otherwise, when the oilfield get into the high water cut stage, the results of adjust will lack. In 2005, take the Second area of Weixing oilfield as the object, to carry out the relevant technical studies.In this paper, the main research areas are to study the development effect of the second area, analysis the existence problems in the process of oilfield development ,to study the adaptation of the current pattern and reservoir, to study the technology boundaries and the economic boundaries of the Putaohua water-flooding pattern,used numerical simulation, reservoir engineering, economic evaluation methods to study the encryption and adjustment potential and the adjustment method, to adjust the way through the development of different indicators, cost-effective evaluation of the Second District to determine a reasonable adjustment method.