Application of air cooled heat exchangers for condensation of natural gas liquids from associated petroleum gas in an oil field in Iraq

Aim. The paper describes a method for increasing the yield of stock-tank oil by reducing oil carryover with associated petroleum gas (APG) to the flare system and decreasing natural gas liquids content in associated gas separated at the central processing facilities (CPF) of the oil field in Iraq by cooling the feed stream in air cooling (AC) units.

Materials and methods. An integrated model (IM) of the field was built including: a well lift models, a wellhead choke models, a model of an oil gathering network, a models of AC heat exchange, a model of material and heat balance of an CPF. The AC performance in oil treatment was estimated. The main advantages and disadvantages of using the proposed technology are shown.

Results. The decision to implement the pilot project using the leased equipment was made based on the results of a integrated assessment. Estimated improvements in the operational mode of the CPF and oil quality were confirmed by analysis of subsequent practical experience in the use of AC: a decrease in the gas factor of oil, unloading of separators, minimization of carry-out of gas condensate, a decrease in density due to retention of condensate in the liquid phase, while the Reid vapor pressure (RVP) remains within acceptable export specification values. It is important that the values of the True vapor pressure (TVP) were recalculated for climatic conditions: this parameter sets the minimum allowable cooling temperatures, and also ensures the safety of transportation by trucks in a hot climate (≥ 55 °C) without evaporation.

Conclusion. An AC unit considered in the article was originally designed for use in another field. Therefore, one of the tasks was to validate the applicability of this AC unit in the oil treatment process for a field with completed infrastructure. The novelty of the study lies in the non-standard use of an AC unit in the oil treatment oil treatment process.

The results of simulation of using AC units in oil treatment and the actual operation of an AC showed increased output of stock-tank oil at the CPF at low capital and operating costs. The decision to replicate the technology in the field was taken following the results of a successful pilot project to maximize the yield of stock-tank oil.

1. Ivanov S.S., Tarasov M.Yu., Zobnin A.A., Zhiryakov V.Yu., Zyryanov A.B. Uvelichenie vyhoda nefti i snizhenie soderzhaniya legkih zhidkih uglevodorodov v neftyanom gaze pri proektirovanii ustanovok podgotovki nefti. Neftyanoe hozyajstvo. 2011, No. 8. Pp. 138–140. (In Russ.)

2. Denislamov I.Z. Samushkova E.S., Imamutdinova A.A. Obosnovanie uslovij ekspluatacii gazoseparatora pervoj stupeni dlya mestorozhdenij s vysokim gazovym faktorom. Problemy sbora, podgotovki i transporta nefti i nefteproduktov. 2021, No. 1. Pp. 9–17. (In Russ.)

3. Otanizyozov Farruh Ihtiyor ugli, Dustkobilov Abdurahmon Bahtiyor ugli, Murtazaev Askar Hakberdi ugli. Vybor optimalnogo davleniya i temperatury na pervoj stupeni separacii pri podgotovke nefti. Molodoj uchenyj. 2020, no. 22. Pp. 125–127. (In Russ.) 4. RD 39-0004-90. Rukovodstvo po proektirovaniyu i ekspluatacii separacionnyh uzlov neftyanyh mestorozhdenij, vyboru i komponovke separacionnogo oborudovaniya. (In Russ.)

4. Tronov V.P., Shatalov A.N., Sahabutdinov R.Z. Vysokie tehnologii separacii nefti i utilizacii poputnogo neftyanogo gaza. Tezis doklada na nauchno-prakticheskoj konferencii «Dobycha, podgotovka i transport nefti i gaza». 2006. Available at https://www.

5. ipc.tsc.ru/conf/unpk/dokl/dok6bug.pdf (In Russ.)

6. Konovalov V.V., Potapov V.N. Opyt kompleksnogo primeneniya tehnologij sbora, podgotovki, transporta i pererabotki poputnogo neftyanogo gaza v promyslovyh usloviyah v PAO «Orenburgneft». Inzhenernaya praktika. 2015, no. 11. Available at https://glavteh.ru (In Russ.)

7. Gas Processors Suppliers Association. Engineering Data Book. 2012. 13th edition. Section M10. Pp.15–16.