Saudi Arabia's Artificial Island Wells: Smart Thinking, Huge Rewards for Smokeless Flowback Option

Abstract

One of the current largest oil increments in the world in Saudi Arabia is undergoing field development. The southern part of the field traverses the Arabian Gulf Sea. The Production Engineering team crossed major hurdles in the development of this field with Causeways construction on artificial islands over drill sites to assess well sites.Flowback options on wells in these drill sites to unload drilling fluids presented key challenges. The flowback objectives included well cleanup, stimulation, production logging, and extended well tests for reservoir characterization requirements. Flowback would also allow conducting electric submersible pumps (ESP) spin tests prior to ESPs installation.A smokeless flaring option considered the heavy crude's characteristics with relatively high H 2 S content, possible emulsions from intermixing with completion fluids, interwell spacing limitations, and the sensitive nature of the nearby challenging marine environment. The choices were between using a conventional flare system and modifying the proposed layout to optimize the project's objectives while respecting the constraints imposed by a sensitive aquatic environment, highly sour crude, space limitations, and work conditions or implementing pre-existing conventional practices with the attendant risks of compromising health, safety, and environment.The authors examine the processes leading to the implementation of a smokeless and an environmentally friendly flowback option. The discussion includes the modifications made to the burner system, and H 2 S removal from the gas and oil phases. Also a new methodology is presented that fully controlled oil and gas flow to the burner to mitigate the risk of burner flameout for the highest burning efficiency, minimizing spills, and enhancing safe operation. The authors examine the pros and cons of other welltest options such as to re-inject produced fluids into the same reservoir, different reservoirs, or injection into water injectors.Key significant technical contributions include the presentation of several practical measures to avoid oil spills, and to guarantee ambient air quality. The welltest layout included several automation systems or the elimination of human interventionto deliver safely the project's objectives. BackgroundThe drill sites sit on artificial islands constructed from piles of gravel and sand in about 22 feet of water. The Causeway concept itself was borne out of a need to protect the beds of sea-grass and algae in X bay, which supply abundant food for aquatic existence. The beds of sea-grass and algae are therefore the perfect home for species like shrimp, dolphins, crabs, fish, sea turtles, oysters, and some endangered classes. A prime objective was to sustainably manage the X field development while preserving this inherited fragile but untainted legacy of the environment. In addition to the sensitive marine habitat, proximity to public areas, limited well spacing, and a relatively high H 2 S amount in the crude all contribute to the challenging nature of thi...

The Evolution of Well Testing Practices From Conventional to Zero Flaring in a Saudi Aramco Oilfield Development

“…Any zones that warm back quickly indicate they are tight and not accepting fluids and therefore need to be targeted for acid treatment. Zones slow to warm back indicate these accepted a larger volume of fluids, acting as thief zones and should be treated with chemical diversion (Arukhe et al, 2012). A multistage matrix acid stimulation was necessary.…”

“…Heavy oil can be problematic for complete combustion and more prone to fall out and producing black smoke. To combat this, several enhancements were included to improve burning efficiency (Dhufairi, M.A., et al, 2012).…”