A New Approach to Well Construction Cost Saving, The Success of Drilling Long Departure Dual Lateral Wells in United Arab Emirates Onshore Field

Morales, Annie (ADNOC Onshore) | Al Yamani, Sultan (ADNOC Onshore) | Salem, Gamal (ADNOC Onshore) | Nava, Jose (ADNOC Onshore) | El Barbary, Abdalla (ADNOC Onshore) | Pham Dang Le, Khoa (Schlumberger) | Diaz, Nerwing (Baker Hughes) | Adams, Adeniyi (Baker Hughes)

OnePetro 

Abstract

Drilling wells with long departure for extended reach applications is indeed a difficult task. Adding dual lateral sections involves increased risks, thus feasibility studies for wells design and execution purposes are critical. However, the success of this challenging campaign has enabled a new way of cost saving for wells construction.

This case study demonstrates the solutions during drilling and completion by using a single surface slot with two strings for deep water and gas injection wells in shallow coastal water field in UAE.

Dual laterals with long departure involve risks associated with drilling and completion, especially for long sections at high inclinations.

The process involves optimization of the well trajectory to minimize the inclination at whipstock setting depth in order to reduce the drilling footage in the dense formations. Optimizing the Bottom Hole Assembly and drilling parameters to improve the rate of penetration (ROP), always targeting shoe to shoe runs; optimizing the retrievable whipstock type selection together with retrieving procedure; improving the completion design in high inclination at nipple depth to be able to set the packer and test the tubing successfully.

Drilling one for two is the most beneficial point that this well construction practice has offered. Exiting from a congested surface location expose to the highest risk of Anti Collision, now reducing to 50% the exposure minimizing HSE risks. Saving surface facility while delivering two reservoir drains for better productivity is the key element for cost reduction. Most importantly, the concept is feasible and proven.

Surface location has become increasingly more congested in this field thus much higher collision risk, drilling and completion technical constraints are being pushed beyond their limit to target deeper and further reach reservoirs. Lessons learnt and recommendations have been captured to establish the basis for continuous performance improvement. This paper presents a novel approach to well construction with increasing efficiency, integrity from all involved parties, reducing operational risks while significantly reducing cost, and ultimately increasing productivity and profitability.