PRODUCTIVITY SIMULATION AND FRACTURING TREATMENT PARAMETERS OPTIMISATION FOR OIL WELLS IN LOW PERMEABILITY BOTTOM WATER RESERVOIRS

For low permeability bottom water reservoir, controlling the vertical propagation of fracture is the key to fracturing treatment. At present, using plugging agent to form an artificial barrier has become the mainstream technology. However, it lacks a quantitative model to describe the influence of fracturing treatment parameters on fracturing effect directly. Authors intended to develop an automatic optimisation tool to provide fracturing treatment parameters for bottom water reservoirs fracturing. First, a new model has been proposed based on the principle of reservoir numerical simulation and considering the characteristics with plugging agent layer in the fracture. The simulation results show that moderate plugging is good for oil production. Second, a genetic algorithm as an optimisation technique is used to obtain a fracturing design that maximises the net present value. Finally, the proposed method has been applied in Luliang oilfield in China. 6 tested wells achieved a significant increase of oil production and decrease of water cut than the 3 offset ones.