**Hydrogels Applied for Conformance-Improvement Treatment of Oil Reservoirs Treatment of Oil Reservoirs**

**Hydrogels Applied for Conformance-Improvement** 

DOI: 10.5772/intechopen.73204

Fernanda G. C. Tessarolli, Ailton S. Gomes and Claudia R. E. Mansur Claudia R. E. Mansur Additional information is available at the end of the chapter

Fernanda G. C. Tessarolli, Ailton S. Gomes and

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.73204

#### **Abstract**

This chapter aims at presenting a review of gelling polymer systems that are commercially available or under academic development with potential to control the anisotropic permeability profile of heterogeneous oil reservoirs. In these reservoirs, the oil recovery and sweep efficiency tend to be low, even after applying secondary and enhanced oil recovery methods, because the injected fluid flows preferably through the matrix's most permeable regions leaving behind part of the displaceable oil retained at the nonswept volume. For that, cross-linked polymers can be used to plug the high-permeability main paths by means of: (i) the formation of an *in situ* hydrogel or (ii) the adsorption or swelling of pre– cross-linked hydrogel within the reservoir pores, thus causing the diversion of the subsequently injected fluid to low-permeability zones and/or preventing the channeling and early breakthrough of the injected fluid (water or gas) in production wells. The selection of the most suitable hydrogel for the reservoir conformance-improvement treatment should take into account the nature of the conformance problem, the reservoir's lithology, mineralogy, temperature, pH value, salinity, and hardness of the formation water, as well as the gelling system toxicity and cost.

**Keywords:** hydrogel, polymer, conformance improvement, reservoir, oil and gas
