Casing design for oil and gas wells continues to evolve to adapt to increasing challenges. The casing program of most wells represents a significant portion of the total well cost, between approximately 15 and 35%. This paper discusses how expandable liner hanger (ELH) technology continues to evolve to meet the needs of an operator with a new thick walled casing design in fields with H2S and CO2. Circumstances are described wherein thick wall casing design was necessary (greater collapse pressure and room for production safety valves). Details are presented describing why the ELH was selected, challenges encountered, development of a new liner hanger to fit the smaller thick-walled casing inside diameter (ID), and how the liner hanger running tool was modified to work inside a smaller casing. Prejob analysis that was performed to help reduce risks while running in hole (RIH) is discussed. Also highlighted are improved procedures, torque and drag simulations, surge and swab simulation, and critical well review exercises.

The operator chose a well design using 10 3/4 in. casing for a larger inside diameter (ID) installation of an arrangement using double electric submersible pumping (DESP). Casing weight of 79.2 ppf was selected to support the pressure load during well production. The ELH system complemented the new heavy wall casing design during construction and installation because of the many benefits it provided, such as high torque, washing and reaming, and multiple setting contingencies. Suitable expandable material was selected for the H2S and CO2 well environment. Two ELHs were used to run into 10 3/4 and 13 5/8 in. casing, 7 5/8- and 10 3/4-in. in liner through a sidetrack with deviation of more than 75° at the bottom, overcoming entrapment issues during the operation, and reaching total depth (TD). The cementing operation was executed successfully and the ELH expanded, leading to a successful operation with zero health, safety, and environment (HSE) or service quality issues. This paper discusses the latest ongoing developments in ELH technology applied using a new casing size and weight during the construction of oil and gas wells with sour service requirements.

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