Creativity and innovation in well delivery are key drivers for overcoming the challenges arising from fields' maturation and the need to maximize the recovery factor via new technology and unconventional ways of problem solving. In spite of steady performance improvements and many broken drilling records achieved, through many years of drilling operations, the South Oman Well Engineering Team (UWS) are continually looking for areas of further improvement and going beyond the previous field records by applying different techniques such as in-depth wells' detailed design, Global Well Delivery Process, Provocative Concepts, Lean, "Out of Box Thinking Approach"etc.,.
Recently; the team has successfully optimized the casing design for one of the most common oil producer well types simply by tapering the bottommost 40 m of the 9 5/8-in. production casing to 7" casing size complete with 7". casing floats. This eliminate the dedicated trip to drill out the 9 5/8-in. float equipment with an 8-1/2" drilling assembly, as the reservoir section is designed to be drilled with 6-1/8" bit and cased with 4-1/2". WWS (Wire-warped screens) including EZIP (Open Hole Swellable Packer). With in excess of 20 of these well designs per year a saving of USD 15,000 on consumables and 8 hours of rig time are realized per well completed. The potential saving is USD 300,000 over the course of the year.
Lean principles have been deployed in the most standard horizontal well type where the team has taken advantage of the programmed 6 hours waiting for wellbore acid soak to lay down the excess drill pipes and prepare the completion tubing in stands. This job, conducted some ±120 times per year represents a saving of USD10,000 per well. The potential saving is USD 1.2 Million over the course of the year
Shallow gas drilling practice has been challenged and updated. The surface hole in South Oman is characterized by medium to hard rock (limestone interbeded by gypsum with little strikes of shale and Anhydrite) of 14 kpa/m fracture gradient. Total losss of drilling fluid in these shallow formations is always seen at around ±420 m depth (UER formation). Traditionally a divertor system is used instead of a BOP when it is thought that the surface formations have insufficient strength for a kick to be shut in with the BOP without breaking down or cratering the surface formations.
The two conditions mentioned above makes the the risk of rig cratering unlikely therefore the use of 13-3/8" Diverter system has been phased out and replaced by 13-3/8" BOP system for the whole well operation. This has saved Diveter system rental cost and installation time. This job is being repeated ±40 times per year saving USD 25,000 per job, a yearly saving some USD 1Million per year.