Precise Wellbore Geometry Preparation and Determination Led to a Successful Installation of Permanent 456-Series ESPs in 5.5-in. Casing
Authors: Hammad Mustafa , Musa Abdulnaser. Alfadel , Musbah Ahmed. M. , Abdellatief Walied. A. , Dakheel Abdulrahem. S. , Sherik Ayoub , Awedan Hassan , Abdulgader Omar , Elhamali Bubaker , Elhajjaji Rami , Bosnina Seraj , Bunkheila Kais , Belhaj Walid 
Published: November 2023

Installing permanent 456-series electrical submersible pumps (ESPs) in old and potentially corroded wells completed in 5.5-in. X17ppf casing involves many challenges and risks such as small clearance of 0.009 to 0.13 in., which could lead to string damage or sticking; uncertainty in casing weight due to limited tally information; a corrosive environment that leads to various types of casing deformation; rugosity; and deposits. In a field in North Africa, slim ESP equipment does not meet the production target per well due to limited flow capacity. In addition, in this field, the number of wells with 5.5-in. completions being converted from gas lift to ESP is growing rapidly to meet the field production target. For these reasons, the operator planned an integrated workover operation that included preparing the wellbore with advanced scraper and magnets, investigating the casing condition and cement status, and determining the feasibility of installing a 456-series string and the desired setting depth with minimal risks.

The candidate wells underwent a cleanout operation using heavy-duty scraping tools to restore the nominal casing inside diameter from any deposits. This heavy-duty scraping tool can leave ferrous metallic debris, which might affect corrosion and cement logs; therefore, multiple runs of a high-capacity magnet were performed to remove all the ferrous debris left in the well. The wells were then logged with corrosion and cement tools to evaluate the casing geometry and cement status to identify any restrictions, oval or deformed spots, or bad cement intervals to assess any potential risks involved in running in hole/pulling out of hole the 456-series ESP string and to determine the best setting depth for production. Finally, a special equipment configuration and running-in-hole procedures were followed to land the 456-series ESP string safely through 0.009 to 0.13-in. clearance at the desired depth.

Six wells underwent a workover operation and were evaluated in terms of wellbore geometry and cement. Some of these wells exhibited excellent geometry condition, and 456-series ESPs were installed at the desired depth without any issues. Other wells exhibited wellbore geometry issues such as different casing weights, oval joints, and casing corrosion or deformation. These wells were evaluated intensively in terms of ESP configuration, design, setting depth, and pump performance, and necessary steps were followed to successfully set the pump at the maximum possible depth. The 456-series ESPs installed in the six wells resulted in production gain of approximately 28,000 BLPD at an average 71% water cut (approximately 8200 BOPD).

The novel integrated approach led to first successful 456-series installation in 5.5-in. casing in North Africa in a challenging condition. This integrated approach helped the operator to save 20% of replacement cost of downhole equipment and eliminate the cost of stuck and fishing operations while maintaining the workover schedule. In addition, the solution enabled the operator to meet the company production target of 100,000 BOPD.