Waterflooding is a well-established technique in the oil industry to improve hydrocarbon recovery in a given reservoir. However, in the absence of profile modification, water injected into the reservoir will go into the high-permeability zones and will bypass the oil-saturated, low-permeability zones. This paper presents the laboratory validation and reservoir simulation of a relative permeability modifier (RPM) used for profile-modification improvement in injection wells. By injecting the RPM within the high-permeability zones, subsequent injected water will be diverted into low-permeability zones to improve the sweep efficiency of the waterflooding project.

This RPM is a water-soluble relative permeability modifier initially developed for water control in production wells. The polymer functions by adsorption onto rock surfaces and effectively reduces water flow with little or no damage to hydrocarbon flow. These treatments are extremely easy to mix and pump, and require no post-job shut-in time. This RPM was evaluated in 5- and 10-ft sandpacks to investigate parameters, such as depth of penetration, diversion properties, treatment injection rate, and polymer concentration. Laboratory results indicate this RPM can effectively penetrate through a 10-ft sandpack, providing permeability reduction to water throughout the length of the porous media. In addition, excellent diverting properties were observed while bullheading the treatment in sandpacks in parallel with significant permeability contrast.

In addition, a 3-D numerical simulator was used to evaluate the performance of the RPM system under different scenarios and varying parameters, such as (1) permeability contrast between injection zones, (2) presence/absence of shale barriers between injection zones, and (3) treatment volumes, among others. This paper presents the results of these simulations and the impact it has on hydrocarbon and water production and the overall profitability of a particular field. In addition, the field implementation of this technology in injection wells is presented.

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