Thickeners for Natural Gas Liquids to Improve the Performance in Enhanced Oil Recovery and Dry Hydraulic Fracking

摘要: Natural gas liquid (NGL), a mixture consisting primarily of ethane, propane, and butane, is an excellent enhanced oil recovery (EOR) solvent. However, NGL typically about ten times less viscous than the crude within carbonate or sandstone porous media, which causes to finger through rock toward production wells resulting in low volumetric sweep efficiency In this work, targeted thickeners are broadly classified into two categories, polymeric thickener small associative molecule thickener. either case, resultant thickened propane butane solution expected be thermodynamically stable, transparent, capable flowing pore throats (~1 micron) rock. In category thickeners, dilute concentration drag-reducing agent (DRA) poly(α-olefin) that has average molecular weight greater 20,000,000 was proposed as for supercritical ethane. High polydimethyl siloxane polymer (molecular ~1,000,000) polyisobutylene (PIB) ~10,000,000) were also assessed potential NGLs. Phase behavior data (cloud points) viscosity induced by these obtained function temperature, pressure concentration. Results indicate most effective component at both dissolving expanding coils. general, enhancement increases with decreasing temperature increasing pressure, reflective increased solvent strength high pressure. Only DRA significant changes concentrations. To best my knowledge, DRA-alkane presented thesis represent polymer-induced reported date first report thickening ethane. Three types associating considered; trialkyltin fluoride, aluminum di-soaps, crosslinked phosphate esters. point) The ester difficult dissolve completely very modest changes, especially Hydroxyaluminum di(2-ethyl hexanoate) insoluble but temperatures above 40oC. hydroxyaluminum mixtures required heating 100oC attain dissolution prior cooling interest. Tributyltin fluoride remarkable did not require dissolution. tributyltin fluoride-ethane results ethane molecule.