A New Conformance-Improvement-Treatment Chromium(lll) Gel Technology

Abstract

Laboratory testing and evaluation of a new chromium(III) [criii] acrylamide-polymer gel technology for conformance-improvement-treatment (CIT) use are reported. This paper is primarily limited to discuss-; ng the ge 1 techno 1 ogy as app 1 i cab 1 e to fracture conformance problems. A H J J J J J+ Experimental: 200,000 MW, 2.7% hydrolyzed, laboratory-grade PHPA at pH 6 and crosslinked at 44:1 PHPA:Cr; all initial polymer solutions were "watery"; 72°F [22°C].

The Effect of Hydrogen Sulfide Concentration on Gel as Water Shutoff Agent

“…At the same time, the concentration of H 2 S in gelants is calculated. Then put HPAM solution and crosslinker into sealed glass bottle and mixed them, then put them into oven at the temperature of 60°C until the gel is fully formed (according to Sydansk's method (Sydansk, 1988)). …”

“…But when the concentration of H 2 S was higher (1 # was higher fully formed. Gelation time is when the gelants change from code A into code G according to the Sydansk's method (Sydansk, 1988). Code A refers to the state that continuous gel can not be detected and the viscosity of gelants is the same than the polymer solution.…”

Dynamic Gelation of HPAM/Cr(III) under Shear in an Agitator and Porous Media

“…It is crucial how to determine the gelation time and gel strength during gelant flow. There are many methods to obtain the static gelation time, such as the code of gel strength [1], the change in viscosity with time [2], the measurement of the storage modulus and loss modulus, application of electrical conductivity and so on. These methods have advantages in themselves.…”

Use of Polymers to Recover Viscous Oil From Unconventional Reservoirs

“…For example, if continuous impermeable barriers separate highpermeability watered-out strata from less-permeable oil-productive strata, one can use cement, mechanical methods, or certain chemical plugging agents to block off the offending highpermeability zones (at the wellbore) so that injected water only enters and displaces oil from the less-permeable zones. As another example, if a fracture or fracture system causes direct channeling between wells, gels can be extruded deep into the fractures to allow subsequently injected fluid to be diverted to displace oil from the rock matrix (Sydansk and Romero-Zeron 2011). This study is directed at a third scenario, where fluids can crossflow between strata but fractures do not contribute significantly to channeling.…”

“…When gels and other blocking agents were proposed to improve sweep in stratified reservoirs with crossflow, it was commonly stated or implied that the material exclusively entered and reduced permeability in high-permeability strata, thereby diverting subsequently injected water into less-permeable oil-bearing strata (Needham and Doe 1987, Chang et al 2006, Choi et al 2010. Unfortunately, this view ignores penetration into and permeability reductions in less-permeable strata (Seright 1988, Sorbie and Seright 1992, Sydansk and Romero-Zeron 2011. In Fig.…”