Polymeric gel system and methods for making and using same in hydrocarbon recovery

摘要

Coacervate gels having excellent shear viscosities and other properties are made with anionic or cationic polymers, a smaller amount of a surfactant having a charge opposite that of the polymer, and a hydrophobic alcohol and an effective amount of a phosphorus-containing compound sufficient to increase the viscosity of coacervate gels up to 3 times as compared to the gels in the absence of the phosphorus-containing compound. The Zeta Potential of the gel is maintained at an absolute value of at least 20. Optional gel promoting additives include betaines and amine oxides. A preferred gel comprises poly diallyl dimethyl ammonium chloride, a lesser amount of sodium lauryl sulfonate, and lauryl alcohol. The gels are particularly useful in well drilling fluids and well fracturing fluids.

主权项

1. An aqueous gel comprising:
a water-soluble cationic polymer in an amount no greater than 1% by weight, an anionic surfactant in an amount less than that of the polymer, and a phosphorus-containing compound in an effective amount between about 0.001 wt % and about 10 wt. %, where the phosphorous-containing compound is selected from the group consisting of mono-alkali metal phosphate (PO(OH)(OM), where M is Li, Na, K, Rd, or Cs, di-alkali metal phosphate (PO(OH)(OM)2, where each M is the same or different and is Li, Na, K, Rd, or Cs, tri-alkali metal phosphate (PO(OM)3, where each M is the same or different and is Li, Na, K, Rd, or Cs, carbyl phosphate (PO(OR)(OM)2, where R is a carbyl group and each M is H, Li, Na, K, Rd, or Cs, dicarbyl phosphate (PO(OR1)(OR2)(OM), where R1 and R2 are the same or different carbyl groups and M is H, Li, Na, K, Rd, or Cs, tricarbyl phosphate (PO(OR1)(OR2)(OR3), where R1, R2, and R3 are the same or different carbyl groups, or mixtures or combinations thereof, where the polymer and the anionic surfactant form a coacervate gel and where the effective amount is sufficient to increase a gel viscosity of the composition, increase a viscosity build up of the composition, and increase gel stability of the composition and where the composition is characterized in that the composition has
a zero shear viscosity of at least 45,000 ora settling rate of no more than 8 millimeters measured by adding 10 mL of 20/40proppant to 100 mL of a 1.1 wt. % gel maintained at 80° C. in a 100 mL graduated cylinder and measuring a depth in millimeters of the gel from a top of the graduated cylinder.