The development of multilateral wells and long-reach wells has become important to maximizing recovery for many oil fields. These technologies are often applied in offshore environments, where large reservoir areas are drained from one or more platforms.
In the late 1980s, long-reach wells started to use existing infrastructure better by drilling beyond the design limits at that time. Several major operators were extending their limits, and, in the late 1990s, BP’s Wytch Farm showed that a horizontal departure exceeding 10 km was feasible. This had a significant effect on the industry because offshore platforms now could be designed for up to 10-km reach as opposed to the early 1980s, where 3-km reach was common. A field could now be developed with one platform instead of three, resulting in enormous savings.
Multilateral-well technology also matured during the past 2 decades. There were many drivers for this development. One of the most important was the desire to increase production in tight reservoirs. Another advantage is directional control. Well stimulation with fracturing has the drawback that the fracture direction is controlled by the in-situ stresses in the rock. Multilateral branches, on the other hand, can be drilled in any direction.
There is a considerable technology development around these technologies. Those that help clear the challenges such as those related to wellbore stability, wellbore friction, equipment limitations, and operational aspects can be considered mature technologies today.
The main benefit from directional drilling is the maximizing of reservoir recovery. From this perspective, multilateral/extended-reach wells may be considered one of the most important means of improved oil recovery.
Recommended Additional Reading
SPE/IADC 163525 Setting Free the Bear: The Challenges and Lessons of the Ursa A-10 Deepwater ERD Well by John Gradishar, Shell, et al.
SPE/IADC 163487 Case History of a Challenging Thin-Oil-Column Extended-Reach-Drilling Development at Sakhalin by Vishwas P. Gupta, ExxonMobil, et al.
SPE 170831 Going Long—Overcoming Challenges in Completing 3600-m Laterals by R. Liston, Step Energy Services, et al.
Bernt S. Aadnøy, SPE, Professor of Petroleum Engineering, University of Stavanger
01 May 2015
Factory-Model Approach Improves Performance of Coiled-Tubing Drillout
This paper presents a factory-model approach to improving CT drillout performance that has been used successfully for more than 3 years and has become standard practice.
Integrated Approach Overcomes Depleted-Reservoir Challenges
This paper describes challenges faced in a company’s first deepwater asset in Malaysia and the methods used to overcome these issues in the planning stage.
Multilateral and Complex-Trajectory Wells
The oil industry is currently undergoing a technological transformation that will add value, improve processes, and reduce cost. Future drilling engineers will have knowledge of robotics, automation, and organizational efficiency, which is highly appealing for recruitment.
Don't miss out on the latest technology delivered to your email weekly. Sign up for the JPT newsletter. If you are not logged in, you will receive a confirmation email that you will need to click on to confirm you want to receive the newsletter.
03 July 2019