The literature data show that up to 20% of the pumped proppant is usually removed from fractures during fracture cleanup and production. As production rate declines, the removed proppant gets deposited in certain sections of the production casing. Decreasing velocities of produced fluids result in proppant accumulation in the casing until one of these sections is completely plugged. The inflow rate is zero within the production intervals located between the toe (far end) of the well and the plugged section. The volume of proppant that can significantly reduce well productivity and recovery factor is a very small fraction (less than 1%) of the volume of proppant pumped into the wells. This situation requires regular cleanup and there is no economically feasible method of removing the proppant deposits from the production casing.
The horizontal wellbore is essentially a “subterranean oil or gas gathering system” that transports produced fluids from the fractures to the vertical section of the well. In real gathering systems, the identification of possible sites for solids accumulation is a requirement of NACE ICDA International standards to assess the integrity of pipelines with respect to the internal corrosion threats posed by the fluids and solids. In some countries, predictive maintenance based on solids accumulation simulations is mandatory for regulated pipelines. Despite the proppant accumulation in horizonal wellbores causes several adverse consequences too, the above-mentioned loss of reserves and failures of downhole equipment, no standard has been established yet to address this problem in the unconventional resources industry.
Realizing this situation, MPECORP launched real-time virtual modeling services for well trajectory optimization and drawdown management to minimize the length of production intervals of horizontal wells blocked by formation solids and proppant plugs formed during production. We follow the ICDA methodologies, wherever it is possible and appropriate, through simulations of 3- and 4-phase flows in LateralFlow™ (a part of the Multiphase Cloud® platform) using models extensively validated against field data for the same fluids and solids, similar operating conditions, and pipelines having diameters similar to those of the production casings of horizonal wells.
Proppant plugs reduced the initial production rate from 5 to 10 % and the recovery factor by up to 45% in many existing wells at four major US unconventional plays. Relatively small changes may dramatically reduce the parameters that influence well performance and recovery factor; these are listed in the attached brochure. Call us at 505-666-1144 or email us at info@mpecorp.com to request a demo.
