A New Polymer System for Water Shutoff Application in Carbonate Formations

Abstract

Excessive water production from hydrocarbon-producing wells can adversely affect the economic life of the well. It was estimated that an average 2.8 barrels of water is produced for each barrel of oil worldwide. Unwanted water production can unfavorably affect well economics owing to handling of the produced water, reduction of hydrocarbon production, and environmental concerns. Naturally, fluids tend to follow in paths of least resistance which, in reservoirs, are often created by the heterogeneous nature of the rock. There are two levels to this heterogeneity; primarily, microscale heterogeneity which could be represented as a simple porous feature distribution; and the second is macroscale heterogeneity which includes layering, natural or induced fractures, and high vertical and horizontal permeabilities. Together can lead to poor conformance and thus need to be corrected. If fractures for water path are in present, then they need to be plugged in order for producing wells to remain in operation. Numerous chemical options are available for addressing excessive water problems. Most of these chemicals are more suitable for Sandstone formations rather than carbonate rocks. It is estimated that carbonate reservoirs restrain more than 60% of the remaining oil worldwide. The objective of this work is to investigate the efficiency recent developed chemical material for carbonate formation. This material presents an innovative technology for both fracture and Supper-K water shutoff agent. An Integrated approach was applied to investigate the efficiency of a new polymer system (a novel adsorption system). A core flooding tests were conducted to evaluate the effectiveness of this chemical system using super-K, and fractured core. An analytical study, environmental scanning electron microscopy (ESEM) and energy dispersive X-Ray microanalysis techniques were applied to characterize untreated and chemically treated core plug samples. The core flow testes indicate significant drops in water production of all high permeability, fractured and wormholed formation. When chemical treatments were placed, the polymer system was able to withstand the differential pressures and did not allow the flow of water in wormholed core, high permeability cores and fractured core. The ESEM results showed the presence of C-rich compounds filling fracture. This suggests that the chemical treatment of the core plug has resulted in some of the used polymer product blocking fractures and pores.

A Review of Recent Developments in Nanomaterial Agents for Water Shutoff in Hydrocarbon Wells

“…Gelation time (GT) is one of the essential parameters for designing successful water shutoff treatments. Most mathematical models for polymer gels fundamentally include one dependent variable, “GT,” and three independent variables, temperature, polymer concentration, and crosslinker concentration. , To study the gelation kinetics of water shutoff in-situ gels, steady shear rate measurements have been widely used. − …”