Experience from drilling a horizontal well in a naturally fractured and karstified carbonate reservoir using a CML MPD system

Geir Ivan Tangen is a Drilling and Well Control Advisor with Lundin Norway AS and is happy to share a wealth of experience from 40 years of being at the heart of offshore drilling operations in the U.S., the North Sea and the Norwegian Continental Shelf. He holds a BSc in Petroleum Engineering from the University of Stavanger.

Summary

In 2015, while coring in the carbonate reservoir in the second appraisal well on the Alta discovery in the Barents Sea, the drill string fell 2 meters and a total mud loss was experienced leading to a well control incident. As a result, the operator has introduced the Controlled Mud Level (CML) system. To date this system has been used on seven wells including two further appraisal wells on the same field and five exploration wells in the area.

In 2017 it was decided to drill a horizontal well in the discovery in order to perform an extended production test in close proximity to the original loss well. Since it is not possible to predict where large karst cavities and natural fractures will be encountered, contingency measures to handle high losses had to be implemented for the horizontal well. During well planning, further risk reducing measures were implemented, including the use of wired drill pipe to improve the management of the wellbore pressure profile.

In this Lunch & Learn we will have a look at the planning processes leading up to the operation and the highlights of the operation itself together with the lessons learned. It elaborates on how wired pipe, used in combination with the CML system, added value to the operation. It shows how it was possible to drill the reservoir section with a low overbalance while managing severe losses associated with encountering karst cavities and natural fractures and still maintaining the fluid barrier. Despite the severe losses encountered it was possible to safely drill and complete the well without any well control event by use of the CML system.

You can join the seminar from London

Chrysaor (London Office)
Address: Brettenham House|Lancaster Place|London|WC2E 7EN

Capacity: up to 6
Meeting room: Triton
Arrival: We will log in 10:15 GMT (11:15 Norwegian time) and be ready to start listening at 10:30am GMT.  
Contact: Ian Stephens ian.stephens@chrysaor.com to save a seat
Lunch will be served at 1130

FORCE seminars have previously been fully booked with waiting lists so you are encouraged to sign up as soon as you know you will attend.

Participation fees:
FORCE members: Free
Non-members: NOK 1000,-
University/student: Free

Please find registration box at the top right of the page. 

Important information:
You can register as a FORCE member and pay "FORCE member" price if you are an employee of a member company.
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Payment is made online by credit card. Please note that no refunds will be given after you have signed up. If you for any reason can not attend the workshop, you are welcome to send a representative, just inform Linn Smerud as soon as there are changes.