Mitigation of fluid loss from underground reservoirs by electrostatically-driven assembly of particles
Compositions are provided for preventing or alleviating loss of fluids from natural or artificial reservoirs formed in subterranean geological formations and methods for deployment of said compositions. The compositions can be delivered to the subterranean reservoirs in any number of steps and are comprised of rock surface adhesion promoter(s), particles that may consist of solids, gels and liquids, crosslinking agent(s) and a liquid medium. The method of the invention uses the composition of the invention in preventing or alleviating loss of fluid stored in a reservoir existing in a subterranean formation. In the method, the composition is preferably provided in a series of weighted or unweighted “pills” for introduction into the reservoir. Such a series may include from one to any number of consecutive treatments. Multiple pills or treatments may be used if needed.
1. A method for mitigation of fluid loss from a reservoirs existing in a subterranean shale formation comprising:
providing the reservoir in the subterranean shale formation, wherein the surface of the reservoir was created by hydraulic fracturing;
conducting an initial treatment of the reservoir, wherein the initial treatment consists of an initial pill of a solution of poly(diallyldimethylammonium chloride) (polyDADMAC) in water containing 0.001-10% by weight of the polyDADMAC;
conducting a second treatment of the reservoir, wherein the second treatment comprises a second pill of a curable anionic latex, wherein the curable anionic latex comprises an aqueous emulsion of poly(2-chlorobuta-1,3-diene) stabilized by sodium rosinate and alkyl sulfates, containing zinc oxide and mercaptobenzothiazole as curing agents, and further wherein the second pill contains 0.001-30% by weight of poly(2-chlorobuta-1,3 diene), 0.001-5% of sodium rosinate and alkyl sulfates, 0.001-10% of zinc oxide, and 0.001-10% of mercaptobenzothiazole; and
allowing a liquid film to form on the surface of the reservoir by the adsorption and coalescence of particles of the curable anionic latex, wherein the liquid film crosslinks with the curing agents to form a layer of water-impermeable chloroprene rubber.
2. The method of claim 1 , wherein the curing agents are supplied as a separate, third pill after the step of allowing the liquid film to form on the surface of the reservoir.