Abstract
Japex has been developing Katakai Oil & Gas field for more than 50 years and accumulated technique and knowledge about drilling. In 2012 and 2013, two challenging wells, Katakai SK-29D/29D-1 and Katakai SK-30D/30D-1, were drilled with some new technique which was focusing on reducing cost and improving productivity.
In Katakai SK-29D/29D-1, 30″ casing was omitted from conventional casing program to reduce cost. And SBM was first adopted to drill mud stone in Katakai field at 12-1/4″ hole section, following knowledge at Yufutsu Oil & Gas field's operation. Consequently SBM maintained good hole condition for 45 days without sloughing and caving of mud stone, therefore drilling period was reduced drastically. At the Green-Tuff reservoir section, multi-branch well was drilled to improving productivity, which is first trial at Katakai field.
In Katakai SK-30D/30D-1, Omitting 30″ casing was conducted following Katakai SK-29D/29D-1. SBM was also adopted at Green Tuff reservoir at 8-1/2″ hole section as well as mud stone. Due to controlling to slough clay mineral in reservoir and reducing torque and drag by SBM, high deviation well was drilled with long distance reservoir section.
This paper introduces about 1)Omitting 30″ casing, 2)Multi-branch, 3)Adopting SBM, 4)Cementing considering well life, 5)Drilling high deviation deep well in hard formation, 6)Taking action for high temperature condition.
