Auto-Gas Lift and Smart Well Completion Challenges to Extend Well Life and Running Toward Cost Effective Program, Field Case Study

摘要

As known the first application experiment for lifting fluids was conducted in Germany in 1797. Then the idea was developed in 1846 utilized compressed air to lift oil from wells. In year 1900 the lifting done by compressed air injected through the annulus or tubing where numerous patents were applied for and issued, but it took nearly 20 years before gas lift became an acceptable lifting method. In 1945 nearly 25,000 different flow conventional valves were patented. Later the pressure operated valve has practically replaced all other types of gas lift valves. The first WL retrievable gas lift valve was introduced in 1957. This pressure with the introduction of the bellows charged gas lift valve in 1940, gas lifting of low pressure wells with a controlled change in the surface injection pressure was achieved. As all the above types is required heavily and costly facility in addition to losing energy, big oil companies such as ADCO started digging for innovative and creative ideas to overcome the disadvantage of the surface injection valves such as corrosion, well control and upstream risk. Although the conventional gas lift system still required but due to harsh environment especially in SOUR fields the Auto-Gas Lift Smart well completion become one of the innovative solutions. Recently ADCO investigated and has successfully installed the first Auto-Gas Lift Smart completion in the UAE. The concept of this completion is to use the gas cap energy from different reservoirs to lift the heavy and high water cut wells. This will eliminate conventional gas lift approach as well as intervention cost meanwhile extends the well life. Candidate selection for this new approach was considered as the main challenge as step one to avoid the project failure. Second main challenge of Auto-Gas Lift was nonstandard completion material and accessories which required special design. As case study this paper will introduce challenges starting from well planning, designing, material selection, and execution. This paper also will demonstrate different problems such as reservoir pressure regime, Slickline line up normal operation through high deviated hole hence it wasn't easy at a high angle to retrieve the plugs, and finally controlling the higher differential pressure of upper formation was also a big challenge. A smart well head was finally installed and tested for the integrity.