Abstract
The new production logging tool string and interpretation technique were established in order to solve the surveillance limitations in the short string section of the dual completion wells. The logging program was initiated in Kuwait Sabriyah Field where there are two major producing formations: Mauddud Carbonate and Burgan Sandstone Formations. The wells were completed with dual production strings due to distinct fluid and reservoir properties in these formations.
Water injection was implemented in Mauddud Formation in late 2000 after a successful waterflood pilot program. The wells having water injection are mostly located in the short string section of the dual completions. The monitoring of the water breakthroughs and finding the bypassed oil became crucial for the field development. Understanding of the reservoir required logging these sections. The conventional wireline logging was regarded as a difficult and unsafe operation due to complicated nature of the production strings and the risk of wireline logging tool entangling. The earlier practice was to utilize the workover rig and to remove the two production strings before performing any wireline logging in the well. This operation was not only costly and time consuming but also pausing the production from Burgan Formation.
The new logging string and interpretation technique were developed to survey the short string section of the dual string completions without utilizing a rig. The logging operation consisted of conveying the production logging tool with a coiled tubing through the short string section of the dual completions. Flow profiles and water entries were confidently obtained in many wells with the new interpretation technique.
This paper presents the history of the short string logging operations in the North Kuwait Fields and highlights the improved coiled tubing conveyed logging tool string and the recent interpretation technique in order to overcome the problems due to completion restrictions.
