The Longest Ultra Slim Hole Lateral Section in the World With Single Run an Integrated Drilling Technology and Geo-Steering Approach
Authors: Sitinjak Eri Sarmantua , Qaddoura Dana , Marwah Gaurav , Alenezi Barak , Al-Khaldy Meshal , Dutta Abhijit , Al-Shammari Altaf , Mohamad Anfal , Elafify Ibrahim , Fadtare Ashish 
Published: November 2020

Objective/Scope (75)

Oilmen have always strived to break technological barriers to reach new heights in searching of Black Gold. In order to create an effort to do so has created world record by drilling the longest Slim Hole Horizontal section in of its deep development well in North Kuwait. The sick well lying dormant was completed as Horizontal Water Injector well through depleted Carbonate zone to augment reservoir pressure and increase oil production in producers. This re-entry well used Ultra Slim drilling technology in order to maximize oil production in the carbonate reservoir. The objective was to support the water injection campaign nearby producer wells in the eastern flank of the field. Limited slim hole logging tool without azimuthal capability and high expectation from client required extra control while drilling with precise geo-steering adjustment. Inability to transmit load during sliding due to sinusoidal buckling in long ultra slim hole, restricts penetration rate and pose challenges to maintain proper wellbore placement. Based on previous experience, we planned to drill this well in multiple runs.

Methods, Procedures, Process (75-100)

Geo-steering pre well modelling is required to be done prior to job execution. The application engineer also worked based on the offset well drilling data to optimize the bottom hole assembly. There was a concern regarding weight transfer, as Sinusoidal Buckling and the subsequent sliding issues are always difficult for this wellbore size. Ultra Slim Hole tool provides only gamma ray and resistivity logging while drilling tool with the current technology. Log responses incorporated with drilling dynamic and drilling parameters data in real time will be the source and justification for the wellbore placement.

Results, Observations, Conclusions (100-200)

Slim Hole Motor successfully drilled the long slim lateral section in one run only which otherwise required multiple runs in previous wells drilled by competitors. Despite the challenges, the logging tools allowed proper wellbore placement and wellbore was successfully maintained inside the target porous reservoir. 4.125inch Talon PDC bit endured drilling stresses and OBM helped reduce friction factor and minimize differential sticking while drilling. The well was successfully executed to total depth covered total footage of 4696 feet, making it the longest ultra slim hole horizontal well in the World. The single run job significantly reduced the drilling cost while drilling the Ultra Slim lateral section. The BHA achieved the required sliding capability to steer the well according to geological observations. The sinusoidal buckling concerns were overcome by finding the weak intervals of weight transfer in the BHA and mitigating them with continuously changing the BHA design by reshuffling the drill collars to get the required WOB.

Novel/Additive Information (25-75)

This will be the world longest Ultra Slim lateral section in single run with no failures.