Application of a Light Rig in Deep Exploration Drilling Operations in Nigeria

摘要

The upsurge in drilling activities in 2004, occasioned by the strong oil prices resulted in a challenging rig market situation such that operators have to plan well in advance to be able to get a rig for the next well campaign. For desperate operators, the only option is innovation or new technology and unusual risk taking. An operator in Nigeria recently adapted a light work over rig of 800 horsepower and 320,000lbs pulling capacity to drill an exploration to 11,000 ft. This was operating the rig at beyond its capacity. Minor modifications were made to the rig to enable the running of casing strings, and operations monitored with the help of wells software, resulting in the successful drilling and abandonment of the A-1x well. The result was a 30% savings of the budget well cost contributed mainly from the slimmer design and lower rig rates of the light 800 hp rig. It is also noted that the light rig was moved in 8 days compared to 23 days planned with the heavier rig. The paper highlights the detailed planning and execution of the drilling phase of the A-1x well and how the capacity issues were addressed leading to the estimated savings of $2million.