Abstract
Proactive reservoir management is key to extending the maximum sustainable production plateau and achieving high recovery factors from any asset. A crucial parameter to monitor over time is reservoir fluid saturation, which is normally addressed with Time-lapse Pulsed Neutron Log data acquisition campaigns. The increasing complexity of secondary and tertiary oil recovery schemes (miscible gas injection) has created an even greater dependency on saturation monitoring tools to better delineate fluid movement within the reservoir.
The offshore fields in the UAE are quite mature, with a large number of wells and all associated infrastructure. Reservoir saturation logging campaigns are made increasingly difficult due to resource limitations - winch boats for equipment movement, slickline units for Down Hole Safety Valve retrieval and Tubing checks as well as offshore living accommodation limitations are major factors, any of which can cause the halt of a rigless logging campaign.
Further to the above logistics factors, the production losses associated with such a campaign due to well shutdowns caused by logging units on WHT compound the problem, as they tend to interfere with production targets, further reducing the number of wells available for monitoring.
A new Memory Pulsed Neutron Logging service has successfully been introduced into the UAE, which avoids these field logistics issues and minimizes production losses caused by saturation data acquisition, without negatively affecting data quality. The successful implementation of the first worldwide Coiled tubing conveyed Memory Pulsed Neutron logging service has further saved the operator time and money in terms of operational efficiency. This paper is designed to highlight all aspects in terms of operations, data quality and positive impact on hydrocarbon production associated with rigless logging operations. Case histories will be used to illustrate the gains. Potential future developments and applications will also be discussed.
