Cementing portion of conductor string
The method of drilling an offshore well from a movable drilling rig and cementing at least a portion of a well conductor pipe string in the well is described comprising: lowering into the ocean floor a large-diameter two-section drive pipe having a first releasable connector means between the upper and lower sections that are connected together just above the ocean floor; providing fluid inlet means through the wall of the lower drive pipe section; providing high pressure fluid conduit means in communication with the fluid inlet means and having second releasable connector means adjacent thereto; driving the lower section of the drive pipe into the ocean floor such that the connector means and the fluid inlet means are above the ocean floor; drilling the upper portion of the well at a selected diameter and to a selected depth through the drive pipe; installing a well conductor in the drilled hole; cementing the well conductor in the well below the ocean floor by pumping cement slurry down through the well conductor; simultaneously pumping liquid down the conduit means to the inlet means below the connector means and injecting the liquid into the cement slurry stream flowing upwardly in the annulus to dilute the cement slurry as it passes the inlet means; stopping the pumping of cement slurry down the well conductor when the annulus has been filled up to at least the ocean floor to form a cement plug in the annulus; preventing the formation of a cement plug in the annulus above the inlet means by continuing the injection of liquid through the inlet means and into the annulus to be discharged from the annulus at the rig; and stopping the pumping of liquid and its circulation up the annulus when substantially all the cement has been washed therefrom above the ocean floor.
- Assignee:
- Shell Offshore Inc., Houston, TX
- Patent Number(s):
- US 4703813
- OSTI ID:
- 5821071
- Country of Publication:
- United States
- Language:
- English
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BUILDING MATERIALS
CEMENTING
CEMENTS
DRILL PIPES
DRILLING
DRILLING EQUIPMENT
DRILLING RIGS
EQUIPMENT
MATERIALS
NATURAL GAS WELLS
OFFSHORE DRILLING
OFFSHORE PLATFORMS
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PUMPING
SEA BED
WELL COMPLETION
WELLS