Patent EA-004614-B1 (EA)
Title: Compositions and methods to control fluid loss in surfactant-based wellbore service fluids
Inventor: MILLER MATTHEW
IPC: C09K8/88
Filed: 2002-02-27
Abstract: 1. A wellbore service fluid, comprising: a carrier fluid; zea viscoelastic surfactant; at least one polymer and at least one crosslinker; said polymer and said crosslinker forming a crosslinked polymer; said crosslinked polymer comprising a three-dimensional polymer network or gel aggregates large enough to form a filter cake and reduce fluid loss; said crosslinked polymer being present in a concentration of less then 1.8 pounds per thousand gallons. 2. The fluid according to claim 1, wherein the polymer is selected from polysaccharides, cellulose, hydroxyethyl cellulose (HEC), polyacrylamides, or starch. 3. The fluid according to any of the preceding claims, wherein the polymer is present at less than about 1.2 pounds per thousand gallons carrier fluid. 4. The fluid according to any of the preceding claims, wherein the crosslinker comprises a metalloid or metal compound comprising an empty d-orbital. 5. The fluid of claim 4, wherein the crosslinker comprises boron present at less than about 250 ppm boron. 6. The fluid according to any of the preceding claims, wherein the viscoelastic surfactant is present from about 3 gallons per thousand gallons carrier fluid to about 200 gallons per thousand gallons carrier fluid. 7. The fluid according to any of the preceding claims, wherein the viscoelastic surfactant comprises a compound selected from erucyl bis (2-hydroxyethyl) methyl ammonium chloride, oleic acid, euric amide propyl dimethyl betaine or oleic amide propyl dimethyl betaine. 8. The fluid according to any of the preceding claims further comprising a fluid loss control additive comprising an inorganic solid or starch fluid loss control additive or mixtures thereof. 9. The fluid according to any of the preceding claims further comprising a breaker. 10. The fluid according to any of the preceding claims, further comprising a proppant. 11. The fluid according to any of claims 1 to 9, further comprising gravel. 12. A method of treating a subterranean formation comprising providing a wellbore service fluid according to any of the preceding claims and introducing said wellbore service fluid into a wellbore under conditions such that a filter cake is formed. 13. The method according to claim 12, wherein the wellbore service fluid is injected into the formation under conditions such that a filter cake is formed at a pressure sufficiently high to fracture the formation. 14. The method according to claim 13 comprising providing a first wellbore fluid according to any of claims 1 to 9, injecting said first fracturing fluid into the formation under conditions such that a filter cake is formed at a pressure sufficiently high to fracture the formation; and then providing a second fracturing fluid according to claim 10 and injecting said second fracturing fluid into the formation at a pressure sufficiently high to fracture the formation under conditions that will result in said proppant being retained in the fracture. 15. A method of gravel packing a wellbore comprising a screen, a formation face and an annular space defined there between, comprising providing a wellbore service fluid according to claim 11, and introducing said wellbore service fluid into a wellbore under conditions such that a filter cake is formed and that will result in gravel being retained in said annular space. 16. A method of gravel packing a wellbore comprising a screen, a formation face, and an annular space defined there between comprising providing a first wellbore service fluid according to claim 11, and introducing said wellbore service fluid into a wellbore under conditions such that a filter cake is formed; and further providing a second wellbore fluid according to claim 11 under conditions that will result in gravel being retained in said annular space. 17. The method of claim 12, wherein the method of treating is a method of drilling comprising operating a drill bit to cause penetration of the earth to form a borehole and said wellbore fluid is a drilling fluid. 18. The method of claim 17, wherein the method of drilling is carried out in the producing zone of a well.