Deep Reading Well Placement Technology Eliminate Uncertainties to Deliver Deepest Lateral Section in Unconventional High Temperature Jurassic Reservoir Case Study from Kuwait
Authors: Farhi Nadir , Abdel Samie Mohamed Ahmed , Nouh Walid Saher , Danash Tarek Mostafa , ElDarmerdash Moataz Mahmoud , Tikhonova Izabella , AlQattan Sarah , Saffar Ali Hussein , AlMutawa Majdi , Al-Ajmi Saad Hassan , AbdulMohcen Naser Bader , Regaey Mohcen Mohamed , Alomar Abdulrahman Ahmad , AlBaer Fahad KHNED , Al-Hindi Khaled Ali , Al-Attar Tarek Fathy 
Published: October 2022

In pursuit of higher Gas production targets in Kuwait, a major campaign was initiated to increase reservoir contact in a tight carbonate limestone formation associated with depositional uncertainties. The primary challenge was to overcome lack of sufficient offset data and ambiguous seismic interpretation. To add to the complexity, the well was overlapping a major fault plane, resulting in several anomalies. A combination of deep-reading mapping and accurate imaging tools in real time was a must to properly land and steer the lateral within less than 9 feet thickness at 14,475 feet true vertical depth. Several sub-seismic faults were encountered while drilling and further complications were present with high temperature anomalies while drilling that exceeded tool temperature rating.

A pre-well model was completed to predict formation behavior and develop an initial trajectory with expected responses for different scenarios as well as identifying optimum landing point parameters. Bottom-hole assembly (BHA) was optimized according to required setup and outputs. Latest well placement solutions combining ultra-deep resistivity reservoir mapping and spectral gamma ray imaging tools were deployed. Tool output was used to correlate to the model and anticipate anomalies in formation behavior while crossing any sub-seismic faults or react to sudden change in dip angles.

During drilling, a steep increase in temperature was observed exceeding tool specifications. This resulted in premature trips, increasing the complexity of the challenge, especially as longer open hole section became exposed. An analysis bases on collecting circulating and non-circulating temperature in different runs, along with correlated mud flow and rotation parameters helped establishing best practices to mitigate the high temperature while drilling within tool operating envelope.

The established best practice helped to extend tool life to continue drilling to the required objective, with no compromise to the reservoir data transmitted in real-time for steering purposes. The final outcome was achieving field record in deep drilling group by completing successfully and precisely the longest and deepest lateral in north Kuwait Jurassic asset area while remaining inside the required reservoir unit and providing insight on further units more than 30 ft. away. The final run was the deepest in terms of true vertical depth in which ultra-deep reservoir mapping tool was utilized for steering worldwide.

The paper focuses on how the output of latest well placement technologies helped achieve the objectives and the approach to develop and apply drilling best practices in real time to achieve this field record. The knowledge and methodology is considered crucial in Kuwait Oil Company's path to achieve the set gas production targets, especially with the increase in planned number of laterals in Jurassic asset.