Objective of this paper is to describe a methodology applied to overcome production logging challenges in a horizontal / deviated, low pressure and high water cut well in order to determine flow profile and zonal phase contribution.
Conventional production logging with Electric wireline in the deviated / horizontal and low pressure wells is becoming a challenge. Measuring an inflow profile and identifying water producing intervals in low pressure high water cut wells require an improved methodology. Electric wireline conductor cable placed inside coiled tubing (CT) creates new opportunities for logging and induces well production while logging.
Subsurface information obtained from recently drilled Jurassic wells indicates presence of hydrocarbon accumulation beyond present limit. A new well has been drilled and completed with 7 inch liner to prove the hydrocarbon in a new reservoir. The well was perforated in underbalanced condition and tested with Drill Stem Test (DST). There are four perforation intervals in the deviated profile. The promising four layered carbonate formations produced 100% water while lifting the well with Nitrogen. Acquisition of flow profile data in this well is vital for decision making. It was required to diagnose the contributing and non-contributing intervals to decide on the suitable remedial action. Low pressure with high water cut reservoir becomes a challenge in measuring inflow profile and identifying water producing intervals.
Electric Coiled Tubing (E-CT) was used to convey the production logging tool while pumping Nitrogen (N2)to lift the well production to acquire inflow profile data. Surface well testing equipment was used to measure the surface flow rates. Shut-in survey and flowing survey were performed to identify presence of water behind casing, cross flow and water entry. Multi-finger Imaging Tool (PMIT) was used to measure the internal diameter of the casing strings to confirm the presence of the perforation intervals.
Well production was induced by pumping N2 through E-CT while production logging. Inflow profile data was successfully acquired from a deviated, low pressure and high water cut well using production logging tool (PLT) attached with coil tubing. Production logging results showed that all of the water production is coming from the top part of the third perforation intervals. During Shut-in Survey, it was observed that no cross flow between the perforation intervals and no observation of flow behind casing above or below the perforation intervals. Furthermore, it was observed that the PMIT logs clearly proved the presence of all 4 perforation intervals. The data acquired using E-CT production logging confirmed the contributing and non-contributing intervals which provided a clear vision to take a remedial action.
For the first time in Kuwait, E-CT was successfully used to record flow profile in horizontal/deviated exploratory well while Nitrogen lifting. This successful application will help to acquire production logging in the wells with similar condition.