Equipment and Methods for Determining Waiting-on-Cement Time in a Subterranean Well
AssigneeSchlumberger Technology Corporation
InventorsPierre Vigneaux, Nicolas C.G.L. Flamant, Thomas Barrou
Life of this patent
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Abstract
Improved equipment and methods for determining the waiting-on-cement time after a cementing operation involve an optic-fiber coil that immersed in the cement slurry downhole. The intensity of a reflected light signal from the coil is monitored versus time. Attenuation of the reflected-light intensity corresponds to the development of gel strength, allowing operators to unambiguously determine when wellbore operations may recommence after a cement job.
Claims40
A method for determining the set time of a cement slurry in a subterranean wellbore, comprising:
- (i) selecting a continuous fiber-optic line having a first end and a second end;
- (ii) securing the first end to a fixed position;
- (iii) securing the second end to a spool, and winding the rest of the line around the spool such that there is sufficient line to form at least one coil crossing when the set time is determined;
- (iv) immersing the spool in the cement slurry;
- (v) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vi) measuring changes in the reflected-signal intensity, thereby informing on the state of the cement slurry in which the spool is immersed.
A method of treating a well comprising:
- (i) pumping a cement slurry in a subterranean wellbore;
- (ii) selecting a continuous fiber-optic line having a first end and a second end;
- (iii) securing the first end to a fixed position;
- (iv) securing the second end to a spool, and winding the rest of the line around the spool such that there is sufficient line to form at least one coil crossing when the set time is determined;
- (v) immersing the spool in the cement slurry;
- (vi) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vii) measuring changes in the reflected-signal intensity, thereby informing on the state of the cement slurry in which the spool is immersed.
A method of cementing a well comprising:
- (i) pumping a cement slurry in a subterranean wellbore;
- (ii) selecting a continuous fiber-optic line having a first end and a second end;
- (iii) securing the first end to a fixed position;
- (iv) securing the second end to a spool, and winding the rest of the line around the spool such that there is sufficient line to form at least one coil crossing when the set time is determined;
- (v) immersing the spool in the cement slurry;
- (vi) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vii) measuring changes in the reflected-signal intensity, thereby informing on the state of the cement slurry in which the spool is immersed.
A method for determining the set time of a cement slurry in a subterranean formation traversed by wellbore, comprising:
- (i) selecting a continuous fiber-optic line having a first end and a second end;
- (ii) securing the first end to a fixed position;
- (iii) securing the second end to a spool, and winding the rest of the line around the spool to form at least one coil crossing;
- (iv) immersing the spool in the cement slurry;
- (v) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vi) measuring changes in the reflected-signal intensity to characterize the state of the cement slurry in which the spool is immersed.
A method of treating a well comprising:
- (i) pumping a cement slurry in a subterranean wellbore;
- (ii) selecting a continuous fiber-optic line having a first end and a second end;
- (iii) securing the first end to a fixed position;
- (iv) securing the second end to a spool, and winding the rest of the line around the spool;
- (v) immersing the spool in the cement slurry;
- (vi) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vii) measuring changes in the reflected-signal intensity and identifying a state of the cement slurry in which the spool is immersed.
A method of cementing a well comprising:
- (i) pumping a cement slurry in a subterranean wellbore;
- (ii) selecting a continuous fiber-optic line having a first end and a second end;
- (iii) securing the first end to a fixed position;
- (iv) securing the second end to a spool, and winding the rest of the line around the spool such that there is sufficient line to form at least one coil crossing when the set time is determined;
- (v) immersing the spool in the cement slurry;
- (vi) generating a light signal from the fixed position and transmitting the signal along the fiber-optic line;
- and
- (vii) measuring changes in the reflected-signal intensity.
Dependencies are inferred from the claim text.