Summary
The exploration and development of deepwater hydrocarbon resources
necessitate the fast evolution of drilling and completion technologies for
deepwater wells. To drill and complete deepwater wells successfully,
sophisticated technologies need to be developed to solve various problems
arising from low temperature, weak formations, shallow water/gas flow,
environmental protection, and high deepwater rig rate.
It is a challenge to develop a good cement slurry that can be used
successfully for deepwater wells under low-temperature environment. Such cement
slurry should have several distinct properties, such as a short thickening
time, a fast transition from liquid to solid, a rapid development of
compressive strength, and environmental friendliness. It usually takes a long
time for conventional cement slurry to set and only limited compressive
strength can be achieved at low temperatures. In addition, most additives used
for the conventional cement have adverse effects on the environment. Therefore,
it is of upmost importance to design an environmentally friendly and
low-density cement slurry that is appropriate for deepwater wells.
In this paper, a new deepwater cement [sulfur polymer cement (SP-C)] was
designed and tested for the first time. This new deepwater cement combines the
advantages of the sulfoaluminate cement and Class G oilwell cement. Green
cement additives including cement dispersant, fluid-loss-control agent, and
accelerator were also developed. Consequently, a unique low-density cement
slurry was obtained for deepwater-well applications. Laboratory tests showed
that the low-density slurry exhibited favorable properties including the
nonexistence of free fluid, an excellent fluid-loss-control capability, a short
waiting-on-cement time at low temperatures, and a shortened transition time of
critical gel strength. This new cement slurry can be easily prepared and
applied in deepwater wells without adverse impacts on the marine
environment.
© 2011. Society of Petroleum Engineers
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History
- Original manuscript received:
10 February 2010
- Meeting paper published:
9 June 2010
- Revised manuscript received:
3 October 2010
- Manuscript approved:
7 October 2010
- Published online:
21 April 2011
- Version of record:
13 June 2011
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