| Popis: |
The demand for environmentally friendly and efficient oil and gas production, especially in unconventional reservoirs, is continuously increasing. Conventional hydraulic fracturing jobs use numerous different harmful (U.S. Environmental Protection Agency, 2016) chemicals to stabilize the fracturing fluid and to maintain its proppant caring capacity. The Bio-Enhanced Energy Recovery (BEER®) fracturing technology is a new technology for clean and efficient energy recovery in tight oil and shale gas reservoirs using biological substances, without the use of environmentally harmful chemicals. This paper shows the potential of the BEER® technology in a tight gas sandstone reservoir with the help of the 3D simulator GOHFER® and laboratory tests. The technology itself consists of two essential parts. On the one hand, a biological hydraulic fracturing fluid to create the fracture and to carry the proppants is just a mixture of a few harmless components. On the other hand, special proppants, based on silicon dioxide, are applied to keep the fracture open. Experiments and lab tests have shown the high potential of the fluid. Fluid rheology, caring capacity, breaking behavior and other relevant properties are examined. The investigations of the proppants result in a very high compressive strength, narrow size range, perfect sphericity at a much lower price, compared to the common commercially available products. Based on those results by the usage of the simulator GOHFER®, the fracturing job efficiency of the BEER® technology is comparable to the performance of the standard fracturing technology. Reservoir properties, the treatment job design, the 3D fracture geometry and post-treatment production enhancement are investigated. A sensitivity analysis of gross fracture length, propped cut-off fracture length, and fracture conductivity confirms the significant potential of this technology. The results presented here indicate that the proposed technology is indeed suitable for performing environmentally friendly and clean hydraulic fracturing jobs, resulting in higher production rates at much lower costs than the conventional technology. |
