From the techniques by which thirteen oil wells with varying degrees of complexity were successfully decommissioned and restored without incidents or accidents, to the application of technology to improve the long-term performance of injection wells to enhance oil recovery, the technical sessions at the SPE- Nigeria Annual International Conference & Exhibition NAICE 2023 organised by the Society of Petroleum Engineers (SPE), Nigeria Council, is a treasure trove of innovative ideas in oil exploration.
Felix Obike, chairman of SPE Nigeria Council in his opening remarks at the Conference on July 31, said that at the core of the SPE NAICE, is the technical programme where academic research and special interest industry projects are presented for learning in two days. A total of 170 peer-reviewed technical papers were presented and BusinessDay attended a few sessions to report on the ideas being presented.
A paper presented on August 1, themed “Bonga Deepwater Project Mid-Life Abandonment Campaign – A Success Story” authored by Osehojie Ojeh-Oziegbe, Augustine Okosun, Oladokun Adubi, Oluwatobi Ugoh, Elesie Ezenwanne, and Timi Jenakumo, all of Shell Nigeria Exploration and Production Company, highlighted the strategies employed by Shell to decommission and abandon depleted wells including in a deepwater environment as they reach their end of useful life.
It is already difficult enough to decommission wells on onshore fields, deepwater wells present a new set of difficulties. The feat was achieved by recovering the completion, production, and intermediate casing strings to expose the reservoirs traversed by the wellbore, then restoring the caprock using cement plugs which were set to create a rock-to-rock isolation of all zones with flow potential within the primary wellbore, the paper noted.
“The objective was to prevent crossflow between reservoir zones, isolate the reservoirs from the environment and marine life while safeguarding all subsea infrastructure from damage arising from the well abandonment operations,” said Augustine Okosun, a Lead Well Engineer at Shell who made the presentation on behalf of the team.
In total, thirteen wells with varying degrees of complexity were successfully decommissioned and restored without incidents or accidents. The fourteenth well had to be suspended due to multiple complex challenges which emerged during the abandonment campaign.
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The engineer said the well needed to be replanned, ensuring the required equipment to execute the emerging challenges was available. The challenges encountered helped shape new ideas. These ideas include achieving better well integrity coupled with improved tubing and casing recovery practices and optimized cement plug placement will be a foundation for future deep water well abandonment in Nigeria specifically and the industry at large. The learnings from the project were adopted to generate a Standard Operating Procedure (SOP) for deep water well abandonment, the paper said.
Another paper presented on August 1, titled “Successful Applications of a New Sand Screen Technology to Mitigate Water Injection Challenges, A Case Study for X Field, Nigeria” presented by Justus Ngerebara, Olusiji Alawode, and Ismail Hamzat, Ross Wilson, James Anderson, and Mojtaba Moradi, TAQA; Ejiro Emifoniye, Ifeanyi Ugbor, and Ngozi Okonkwo, Shell Nigeria Exploration and Production Company Limited, highlighted a number of techniques been applied to improve the injectivity and therefore long-term performance of injection wells to eventually enhance oil recovery in one of the fields in Nigeria.
To combat the challenge of water presenting compromising well integrity, the researchers selected a new sand control technology that provides full access to the lower completion sand face during injection and/or intervention without restriction or pressure drop and can withstand well conditions for the entire well life. The paper highlights the rigorous compatibility tests and practices, including modelling, backflow, cross flow, erosion, and plugging tests that were performed to ensure that well completions and operations requirements were met for the field.
“The results from all studies were positive and successful, and therefore, the technology was approved to be installed in the wells,” said Justus Ngerebara.
Still, on production enhancement, another paper titled “Implementation of One-Trip Acid-Jetting Solution in AX field for an Operator in Nigeria” written by Justus Ngerebara, Olusiji Alawode, and Ismail Hamzat, of Shell Nigeria Exploration and Production Company Limited; and Jesse Gerber, Oluwaseyi Olaobaju, Jombo Onuoha, Omar Espinoza, and Colin Andrew of Baker Hughes, highlighted how the service provider worked with the engineers to use a jetting-tool to deliver acid treatment to an oil field whose injectivity performance has been on the decline mostly attributed to poor sand development.
The technical sessions featured paper presentations by engineers who were engaged in the daily operations of oil drilling and field management thus enabling shared learning.
