Drilling and cementing with phosphate
AssigneeShell Oil Company
InventorsKenneth M. Cowan, Arthur H. Hale
Life of this patent
Estimating the term…
Abstract
A drilling and cementing process wherein a drilling fluid containing a metal compound which is a proton acceptor component is utilized, thereby laying down a filter cake. Thereafter, the drilling fluid can be combined with a phosphorus acid to give a cementitious slurry which is thereafter used in a cementing operation. Alternatively, a phosphorus acid such as polyphosphoric acid is circulated into contact with said filter cake.
Claims15
A method for drilling and cementing a well, comprising:
- combining constituents comprising water and a proton acceptor metal compound selected from the group consisting of CaO, MgO, and ZnO to produce a drilling fluid;
- thereafter utilizing said drilling fluid in a well drilling operation to form a borehole, thus producing a used drilling fluid;
- thereafter combining said used drilling fluid with a stoichiometric amount of phosphorous acid to produce a cenentitious slurry;
- and
- utilizing said cementitious slurry in a cementing operation.
A method for drilling and cementing a well having a restricted annulus comprising:
- combining constituents comprising water and a proton acceptor metal compound selected from the group consisting of CaO, MgO, and ZnO to produce a drilling fluid;
- thereafter utilizing said drilling fluid in a well drilling operation to form a borehole, thus producing a used drilling fluid;
- thereafter combining said used drilling fluid with a stoichiometric amount of phosphorous acid to produce a cementitious slurry;
- and
- utilizing said cementitious slurry in cementing said restricted annulus.
A method for drilling and cementing a well, comprising:
- combining constituents comprising water and a proton acceptor metal compound comprising magnesium oxide to produce a drilling fluid;
- utilizing said drilling fluid in a well drilling operation to form a borehole, thus laying down a filter cake and producing a used drilling fluid;
- contacting said filter cake with a phosphorous acid to produce a set filter cake;
- introducing a pipe into said borehole;
- passing a cementitious slurry comprising a combination of additional proton acceptor metal compound comprising magnesium oxide and a member of the group consisting of polyphosphoric acid, ammonium polyphosphate and monoammonium phosphate into said pipe;
- and
- displacing said cementitious slurry down said borehole and up into an annulus surrounding said pipe by direct fluid contact between seawater and said cementitious slurry.
Dependencies are inferred from the claim text.