Innovative Pressure Assessment & Mapping in a Giant Carbonate Reservoir Brown Field Under Water Flood Development
Authors: Al-Shuaib Mariam , Chetri Hom , Orjuela Jaime , AL-Harami Khalid 
Published: November 2016

Sabiriyah Mauddud is a giant reservoir in NK under active water flood with about 200 producers and 32 injectors. The reservoir has no aquifer or insignificant energy support and had been on production since 1960s. Water flood started in the year 1997, initially with a pilot and later on expanded to the full field in a phased manner. Initial development was on pattern flood concept with all vertical injectors & producers which has now been replaced with Produce High-Inject Low (PHIL) concept using horizontal wells. In light of the significance of this reservoir for Kuwait's production, all efforts are made to optimize the performance of this reservoir. To achieve this objective, Pressure monitoring & performance analysis is considered to be the backbone of all production as well as injection activities.

This paper presents the methodology conceived and implemented to assess the reservoir pressure performance and estimate the current reservoir pressure in different segments/ blocks in an innovative way so as to maximize the value of "Water flooding" in North Kuwait area along with the meeting of production aspirations using ESP as artificial lift system in an optimized manner. Except the RFT data in newly drilled wells, the availability of pressure data was limited during recent past, making it necessary to integrate all the available information so as to build a powerful tool to be used for water flood monitoring. All available information – Repeat Formation Tester "RFT", Static Bottom Hole Pressure "SBHP" and Pump intake pressure "PIP" under dynamic and static conditions, were collected & analyzed. An initial study related to compartmentalization showed two main areas, north and south, based on comprehensive analysis of all the pressure points. The analysis also helped for identifying areas with good vertical connectivity and understanding segments with vertical barriers matching with the geological description. In order to have the latest pressure mapping, data were combined to have an integrated imagery of the pressure distribution across the reservoir. During the exercise, "Gaps" were identified which were filled in by the intake pressure live data as well as shut in data to have a meaningful mimic of the reservoir pressure to help the ongoing production as well as injection activities.

Based on the innovative approach as above, surveillance plan has been made to further enhance the quality of the mapping. Several maps such as opportunity map; PVT properties map; layer wise pressure maps etc. have been generated for ready-to-use information to facilitate daily operations.

The objective of the paper is to share the innovative, simple, smart and very useful approach adopted by North Kuwait to manage the giant Mauddud. This paper presents the methodology conceived and implemented to assess the reservoir pressure performance and estimate the current reservoir pressure in difference segments/ blocks in an innovative way so as to maximize the value of "Water flooding" in North Kuwait area along with the meeting the production aspirations using ESP as artificial lift system in an optimized manner.