Improving Drilling-Operation Efficiency by Use of a Mud Cap

Topics: HP/HT
Fig. 1—Well location map.

This paper describes the planning and execution of use of mud-cap fluid in the drilling of an ultranarrow-margin (0.50-lbm/gal window at the planning stage) high-pressure/high-temperature (HP/HT) well from a jackup rig. Significant operational efficiency was gained from the use of cap fluids, making it possible to drill a well that otherwise would have been nearly impossible to drill with minimum lost time.


The IM field is located in Block MLHP-7 in the Rio Del Rey basin offshore Cameroon in a water depth of 58 m (Fig. 1 above). At the target reservoir level, Well IM-5 was predicted to be a marginal HP/HT well with an estimated reservoir temperature of 181°C and a reservoir pressure of 9,971 psi (16.80 lbm/gal) at a depth of 3475-m true vertical depth subsea (TVDSS).

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 167985, “Improving Drilling-Operations Efficiency on an Ultranarrow-Margin HP/HT MPD Well by Use of a Mud Cap,” by Joy Oyovwevotu, SPE, Senergy; Eric Low, SPE, Bowleven; and Steve Nas, SPE, Schlumberger, prepared for the 2014 SPE Drilling Conference and Exhibition, Fort Worth, Texas, USA, 4–6 March. The paper has not been peer reviewed.
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Improving Drilling-Operation Efficiency by Use of a Mud Cap

01 April 2015

Volume: 67 | Issue: 4


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