Abstract

Clay swelling, dispersion, and migration frequently create flow problems insubterranean structures subjected to steam or other thermal recover: methods. Available literature concerning the effectiveness of clay stabilizers in steamor hot water environments is limited.

Thermal recovery methods are predicted to play a vital role in furtherdevelopment of many hydrocarbon reservoir. Effective control of clays should beachieved to facilitate greater and more economical depletion of existing andyet to be developed reservoir.

Several commercial inorganic and organic clay agents were evaluated in thelaboratory for retention of clay stabilization properties when expose to 300 °C(422 °K) to 600 °F (588.7 °K) steam. Stand packs containing clays were treatedwith clay stabilizers, then subjected to dynamic steam flow conditions. Thesteam, passing through each porous test specimen, was condensed and analyzedfor evidence of clay stabilizer residues. Accumulated steam throughput volumes(water equivalent) were measured to determine relative flow characteristics ofdifferent clay stabilization chemicals. Results were compared to tests sandsnot treated with any clay stabilizer. Clayey test sands were exposed to sixhours of steam flow. Each steamed clayey sand was evaluated for claystabilization properties before nd after treatment with hydrochloricacid.

Data indicate that currently that currently available organic and inorganicclay stabilization agents can be beneficial in maintaining greater sustainedformation permeabilities in clayey formation subjected to steam and hot waterflooding. Findings showed that clay stabilizers vary in retention of claystabilization properties during and after steam treatment and in resistance tohydrochloric acid stimulation treatment.

Introduction

It has been reported that oil received by steam recovery methods represents 90%of the oil produced by all of the current enhanced oil recoverytechniques1. Steam recovery methods will become even more widelyused as more of the very viscous oils are recovered. Although steam floodinghas generally been restricted to reservoirs containing low gravity crudes, application in light oil-bearing structures may become more common. Steamflooding of several light oil-containing formations has shown this processsignificantly reduces oil saturation remaining after waterflooding.

Steam injection encompasses the entire recovery spectrum involving primary, secondary, and tertiary techniques. Primary recovery of the very viscous orsemi-solid oils from tar sands constitutes one or the most important productionmethods for these oil sands in Alberta. Steam recovery technology is advancingas the application scope expands. The C.S Department of Energy is supportingresearch related to development of chemical additives for application withsteam injection to increase oil recover. Current work is concerned with lowtension agents which will function is steam environments and chemical systemsfor plugging or reducing aggressive steam input into high permeabilities steakswithin a heterogeneous formation. Steam injection profile control can beachieved only with the development of materials that will not decompose in therock matrix when exposed to high temperature steam.

The purpose of this paper is to present findings which may contribute to steamrecovery termology in the area of controlling clay minerals.

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