Restoring the Auca Field Potential Through Formation Damage Removal

Flow assurance has been a big focus of oil and gas operation in ensuring the delivery of the targeted production. A few fields located offshore Malaysia have been experiencing solid deposition inside tubing and stable micro-emulsion from early stage of their life. Oil production from Field W begin in January 2003, unfortunately the wells produced viscous stable emulsion which caused the production decline significantly. Multiple analyses and efforts, including chemical and mechanical treatments, conducted over the years with minimal success. The damaging mechanism was determined to be caused by rare organic deposit that have caused a significant pressure drop in the tubing, which consequently restrict oil production and tested to only disperse at above 90°C. It was suspected that the organic deposit was a naturally occurring component of the crude oil itself, separating from the bulk of the crude as a consequence of the fluids movement towards the wellbore and the consequent drop in fluid pressure. This paper focuses on the step-by-step workflow developed to identify the solid deposition, laboratory testing, treatments conducted and the result of different chemical treatments in Field W. The ultimate effort was by developing an advanced eco-friendly nano-fluid to remediate the rare issue of High Molecular Weight Organic Deposit (HMWOD) in the fields. The nano-fluid pilot treatment was conducted in 2014 and successfully rejuvenate the well with total of 20,000bbl incremental oil volume. Early 2018, subsequent treatments were conducted that contributed substantial improvement to the field production and at lower total treatment cost. This advanced chemical using nano-fluid technology concept is deemed feasible and will be further replicated in other fields. This paper is highly beneficial to Operators, Petroleum and Flow Assurance Engineers experiencing flow assurance issue on organic scale such as microcrystalline wax, high molecular weight wax and stable emulsion in the crude production. This paper also promotes the use of nano-fluid technology as part of the solution to flow assurance issue in Oil and Gas industry.

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Forty-Seven–Well Case Study: How a Holistic ESP Design for Deep Deviated Wells with Low Flow Rates Achieved Economic Production

Camilleri¹,

Villalobos

Escalona

et al. 2021

Day 2 Tue, October 05, 2021

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The Shaya wells have vertical depths of 11,000 ft and are heavily depleted. They, therefore, require 10,000 ft of lift to achieve the target drawdown. Electrical submersible pumps (ESPs) were deployed, but because of the low flow rates (80 B/D), produced solids, and high free gas content, initial run lives were uneconomical. This 47-well case study demonstrates how a holistic design and operating procedure achieved both the target drawdown and an economical mean time between failure (MTBF). "Learning from history" was the key method as there was sufficient ESP data to determine the root cause of ESP failures based on a combination of dismantle inspection and failure analysis (DIFA) and operating conditions. Moreover, production testing combined with real-time downhole gauge data enabled inflow characterization with both nodal and pressure transient analysis, thereby establishing the well potential and ensuring that the new proposed design was not only reliable but also achieved the targeted drawdown. An additional requirement was to handle both the current low rates and higher rates associated with future waterflooding. A historical review of 9 wells was conducted, followed by a new ESP design that was proposed and installed in 47 wells, which achieved an MTBF of over 940 days, whereas previous designs in the same wells had an MTBF of only 650 days. This substantial improvement was achieved without compromising drawdown as the wells were produced with a flowing intake pressure of approximately 250 psia at setting depths of 9,500 ft. This result is particularly noteworthy when one considers the harshness of the well conditions and, in particular, bottom-hole temperatures of 240°F, fines migration, deviated wells with doglegs above 2.5°/100ft, intake pressures below bubble point and low productivity indices (PIs) of 0.2 B/D/psi. The high depletion combined with low PIs, which resulted in very low flow rates of as low as 50 B/D, was the most challenging factor of this application. Outflow modeling and wellbore hydraulics were also important considerations to limit solid fallback due to insufficient velocity in the production tubing as well minimize heat rise caused by startup transients, which can be long in low-PI wells. ESPs are traditionally best suited to wells with liquid rates providing sufficient cooling for both the motor and the pump as well as short unloading transients during startup. This success story, therefore, provides an important reference for future ESP applications in very low flow rates in deep wells, which are beyond the recommended application envelope of alternative low flow rate artificial lift solutions such as progressive cavity pumps and sucker rod pumps.

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Restoring the Auca Field Potential Through Formation Damage Removal

Cited by 6 publications

References 5 publications

“We Are All Indigenous!” Insurgent Universality on the Extractive Frontier

“We Are All Indigenous!” Insurgent Universality on the Extractive Frontier

High Molecular Weight Organic Scale; A Sticky Journey in Finding the Solution

Forty-Seven–Well Case Study: How a Holistic ESP Design for Deep Deviated Wells with Low Flow Rates Achieved Economic Production

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