Foamed gel employed as a drilling fluid, a lost circulation fluid, or a combined drilling/lost circulation fluid
AssigneeMarathon Oil Company
InventorRobert D. Sydansk
Life of this patent
Estimating the term…
Abstract
A process employing a foamed gel in a wellbore as a drilling fluid, lost circulation fluid, or combined drilling/lost circulation fluid during the wellbore drilling operation. The foamed gel is formed from a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas.
Claims24
A process for drilling a wellbore from a wellhead at the surface into a subterranean formation for production of hydrocarbons, the process comprising:
- placing a foamed gel in a wellbore being drilled, wherein said foamed gel comprises a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas;
- and
- substantially plugging a wellbore face of said wellbore with said foamed gel to prevent significant lost circulation of fluid from said wellbore across said wellbore face into a surrounding formation.
The process of claim i wherein said foamed gel has a hydrostatic pressure gradient in said wellbore less than the fracture or parting pressure gradient of said formation.
A process for drilling a wellbore from a wellhead at the surface into a subterranean formation for production of hydrocarbons, the process comprising:
- mixing a foamed gel and a substantially gel-free drilling fluid to form a combined drilling/lost circulation fluid, wherein said foamed gel comprises a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas;
- placing said drilling/lost circulation fluid in a wellbore being drilled;
- and
- circulating said drilling/lost circulation fluid through said wellbore to transport rock cuttings to the surface while substantially plugging a wellbore face of said wellbore with said drilling/lost circulation fluid to inhibit lost circulation of fluid from said wellbore across said wellbore face into a formation surrounding said wellbore.
A process for drilling a wellbore from a wellhead at the surface into a subterranean formation for production of hydrocarbons, the process comprising:
- placing a foamed gel in a wellbore being drilled, wherein said foamed gel comprises a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas;
- and
- circulating said foamed gel through said wellbore to transport rock cuttings to the surface.
A process for drilling a wellbore from a wellhead at the surface into a subterranean formation for production of hydrocarbons, the process comprising:
- placing a foamed gel in a wellbore being drilled, wherein said foamed gel comprises a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas;
- and
- circulating said foamed gel through said wellbore to transport rock cuttings to the surface while substantially plugging a wellbore face of said wellbore with said foamed gel to inhibit lost circulation of fluid from said wellbore across said wellbore face into a formation surrounding said wellbore.
Dependencies are inferred from the claim text.