Simulation And Application Of Different Well Completion Methods In Horizontal Wells

Horizontal well boasts advantages like improving the dynamic reservoir profile, increasing the production for single oil-gas well, etc. Therefore, it is widely applied in various developments of oil and gas deposit. Meanwhile, the completion technology for horizontal well is developing rapidly. However, the complicated well structure makes the geometrical morphology of fluid in the well even more complex. For example, heel-toe effect will cause uneven bottom water cresting and lead to serious flooding in the bottom of the oil well which lowers the final recovery rate. Choosing the proper well completion method can realize the efficient development of horizontal well while accurate simulation of the dynamic condition of fluid in the shaft is the key and the premise.Traditional horizontal well simulation technology rarely took the influence of well structure on fluid in the shaft into consideration,and there has been no particular calculation methods based on model, so accurate and effective simulation of horizontal flow was impossible. In this essay, we base on the principles of equivalent seepage, apply the node-analysis method, consider the oil-gas-water three-phase fluid, and establish the dynamic network model for multi-phase fluid in horizontal well. We also have made some improvements on approaches including Slotted Liner, Open Hole Completion, Selected Blind Liner and Nozzle ICD Completion. Then according to the additional pressure of different complete wells, we calculate the pressure and flow distribution for the horizontal part under the same FBHP and different completion approaches. The following are what we come up with:(1)When using the model to calculate, we should choose a reasonable starting value to improve calculation accuracy and we should divide it reasonably based on horizontal length and engineering requirements.(2)The calculation results can clearly reflect the influence of heel-toe effect. The pressure for horizontal segment decreases from the heel to the toe, and the pressure drops faster if it’s closer to the toe; the higher the differential pressure between the oil pool and the shaft, the bigger the radial flow. While the radial flow accumulates in the horizontal segment, the flow there gradually increases from the toe to the heel.(3)The calculation results reflect that completed well by Selected Blind Liner enters the control section by oil pool packer and annular inflow restriction fluid. The Nozzle ICD eases the influence of heel-toe effect leading to extremely low differential pressure between the heel and the toe. But this type of well completion approach could sacrifice the production capacity of the horizontal segment.(4) According to the calculation results, in real practice, ICD is more suitable for oil pool with high permeability and production. The nozzle diameter should be carefully chosen according to engineering and cost requirements.(5)Analysis on practical cases shows that this model can relatively accurately evaluate the on-spot application of ICD, which is of reference value for real application.The model established in this essay can accurately simulate dynamic condition of fluid in the shaft of horizontal wells with different completion approaches. It also sheds some instructive significance on the optimization of choosing the proper approach for well completion.