An Innovative Approach for RPM Gel Water Shut-Off Simulation

Abstract

Since the potential of relative permeability modifying (RPM) gels for water shut-off was discovered, many researchers focused on understanding the mechanisms by which, these gels perform their disproportionate permeability reduction (DPR) behavior. The focus on this concept and developments in experimental methods and laboratory equipments, have led to clearer and reasonable explanations for the mentioned behavior of these gels. However, the focus on the experimental scope of these gels has resulted in lack of studies on the numerical simulation of the RPM gels injection in the reservoir. In this paper, it is tried to use the achieved experimental knowledge by the mentioned experiments, to analyze the feasibility of the current approaches and to come up with a new approach. Polymer option of commercial black oil simulators is the first approach analyzed and it is proved that using this approach results in false prediction of the relative permeabilities in the treated cells after gel adsorption. The reason is the assumption of the simulators about the effect of the polymer adsorption on oil relative permeability reduction. An alternative to polymer option is defining the gels as solid particles and interpolating the relative permeabilities between the initial and treated sets as a function of the defined solid particles adsorption to the rock surface. Since solid particles cannot be present in the injecting stream, they have to be defined as liquid particles and turned to solid phase in the reservoir via the reactions. Defining reactions necessitates having the simulation in compositional model which is sometimes not favorable due to larger run times and required PVT data for fluid modeling for a compositional run. Surfactant option has the interpolation capability too and it is run in black oil model. In other words it has the capabilities of the compositional approach, but due to its black oil formulation, run times are shorter and no fluid modeling is required. However, using surfactant option of a simulator, changes the capillary pressure and results in reductions in interfacial tension between oil and water. These EOR effects of surfactant presence in the reservoir has to limited by manipulating the defined functions. The approach is then validated against a single well treatment observed data and could reproduce the observed production rates in the 18 months period after the treatment. Validation of the approach permits us for using this approach to simulate RPM treatments in different scales.

Application of Hydrogels and Hydrocarbon-Based Gels in Oil Production Processes and Well Drilling

“…In addition, the depth of penetration is not taken into account explicitly, which prevents the description of the process of the subsequent recovery of the watercut. However, it is possible to use the results of analytical calculations in commercial hydrodynamic simulators (Black Oil) to predict not only the starting indicators, but also the dynamics of operating indicators during the time of the effect [183][184][185][186][187].…”