Efficient Development Method for High-Viscosity, Complex Fault-Block Reservoir

Abstract

XXX unit of Huabei oilfield, a complex fault-block and high viscosity reservoir, has stepped into middle period of development. Though the water cut has reached 81%, only 4.7% of the original oil in place (OOIP) has been produced, indicating that the current development method for this block may be inappropriate.In order to improve the production performance of this block, we studied the proper development technique on the basis of its geologic features. We examined the applicability of combining individual layers, and determined the upper limit for the segments of an injector as well as the optimal injection rate for each segment. In addition, we estimated the reasonable well density, the oil production rate, the injection-production ratio, and formation pressure using both numerical simulation and reservoir engineering method.We further coupled reservoir simulation with an optimization algorithm to provide proper measures for the improvement of oil recovery. The first measure examined is to divide layering segments and complete the well pattern. Our simulations give the optimized position of new wells. The primary oil recovery of two layering segments increases by 2.33% and 1.75%, respectively. The second one is the optimization of liquid production rate. In comparison with the current development state, the optimized schedule will increase the primary oil recovery of the two segments by 2.1% and 1.2%. Therefore, the optimized technique may serve as an effective approach to develop other fault-block reservoirs.In this work, several development methods demonstrate a significant effect to enhance oil recovery for complex fault-block reservoir, which can give a good guidance for other similar reservoirs.

N2-foam-assisted CO2 huff-n-puff process for enhanced oil recovery in a heterogeneous edge-water reservoir: experiments and pilot tests

“…p f is the injected foaming agent cost, $ per kg. p w is 0.66$ per m 3 , p N 2 is 0.1$ per m 3 , p CO 2 is 0.15$ per m 3 , and p f is 4.82$ per kg for the operations in Jidong Oileld, China. Then, the net present value (NPV) was calculated as the discounted sum of the cash ow, which can be calculated as follows:…”

“…Since the operations mentioned above were between the year of 2015 and 2016, p o was set as 46.64$ per bbl. p w is the injected water cost, $ per m 3 . p g is the injected gas cost, $ per m 3 .…”

“…p w is the injected water cost, $ per m 3 . p g is the injected gas cost, $ per m 3 . p f is the injected foaming agent cost, $ per kg.…”

“…Edge-water-driving reservoirs are widely distributed in China, which account for important proportions of geological reserves of crude oil. [1][2][3][4] The existence of edge water has both advantages and disadvantages for the development of oilelds. On one hand, edge water can provide energy for oil production and maintain the formation pressure.…”

Asynchronous Injection-Production Process: A Method to Improve Water Flooding Recovery in Complex Fault Block Reservoirs

“…In water flooding production, AIP is a potential technology to improve oil recovery by alternative opening of the injector and producer to change the distribution of pressure and fluid saturation in the reservoir. AIP technology has achieved certain success in the complex fault block reservoir [16][17][18]. However, there are still some defects in AIP technology, which are mainly shown in the two respects: (1) the effectiveness is not clear and the degree of effectiveness is not unified.…”