Abstract

Extensive oil sand deposits are found worldwide, with the largest and most significant reserves located in Canada (approximately 2.2 trillion barrels) and Venezuela, followed by smaller accumulations in Kazakhstan and Russia. Collectively, the volumes of unconventional oil contained within these oil sands surpass the conventional reserves of all other nations combined. If even 30% of this resource were technically and economically recoverable, it would be sufficient to meet North American energy demand for more than a century, based on 2002 consumption levels. These reserves therefore represent an abundant supply of oil with considerable economic significance. The extraction and transportation of oil from these deposits demand advanced technological approaches. Of the various extraction approaches available, CHOPS, Cold Heavy Oil Production with Sand, has established itself as the leading method for recovering heavy crude oil. This non-thermal process involves the controlled initiation and maintenance of sand influx into production wells, facilitated through the use of progressive cavity pumps (PCPs). The approach not only improves production rates but also provides operational reliability. As sand is mobilised, wormholes are formed within the reservoir, generating significant pressure drops along their lengths. The effectiveness of CHOPS is primarily attributed to two mechanisms: the formation of wormholes and the occurrence of foamy oil flow. Typical CHOPS recovery factors are still very low, around 5–15%; and it can be increased during the Post-CHOPS processes only 2–8%. Also, during the CHOPS process, there are some technical challenges which have been described in our current study.