Although various logging challenges in highly deviated and horizontal wells have been addressed in many previous studies, only a few investigations have focused on emulsion diagnosis and multiphase production log (MPL) solutions in such difficult conditions. The emulsion discussed in this paper is water-in-oil emulsion, in which water is present in the form of droplets dispersed in oil. This is generally expected to happen in a high velocity, turbulent flow regime, and in a low density contrast between oil and water. The impact of water emulsion is the inability to identify and quantify water entries using the standard holdup measurement arrays, because the water droplets have the same conductivity as oil and travel at the same velocity as oil, regardless of well deviation.A novel workflow and methodology were established for successful diagnosis of this emulsion downhole to be able to perform inflow profiling for these problematic wells, using information from different sources of data: multiphase production logging tool (MPLT), pulsed neutron logging tool (PNLT), and surface fluid sampling. The workflow includes job preparation, real-time monitoring during logging operation, and post-job data interpretation.The optimized workflow was applied to field examples for successful diagnosis of the emulsion and the integrated logging solution to overcome this challenge in horizontal wells. This led to the determination, with high confidence, of the downhole flow profile and to the accurate quantitative identification of the source of water production. The information can then be used to plan suitable well intervention, without which the reservoir and/or field development could not be optimized.

Flow profiles of horizontal wells in heterogeneous or fractured reservoirs are usually nonuniform and are frequently characterized by high flow capacity from streaks in high permeable zones or fractures. The nonuniform flow usually causes early water breakthrough that ultimately undermines well productivity. In homogeneous reservoirs, water (or gas) breakthrough commonly occurs at the heel of the lateral section. In either case, whether in homogeneous or heterogeneous reservoirs, achieving uniform flow along the wellbore in horizontal wells to improve sweep efficiency and maximize oil recovery, requires application of advanced well completions that are guided by effective reservoir evaluation and management practices.Optimizing inflow profiles in horizontal wells requires good understanding of multiphase flow mechanisms, where the flow regimes are usually complicated due to stratification, slug flow, mist flow and/or other complex flow behaviors. Achieving better understanding of this multiphase flow mechanism was facilitated with the availability of the multiphase production logging tool (MPLT), which has been utilized extensively in this case study. This paper presents a summary of the results of a case study of 31 horizontal wells completed in a large carbonate onshore field, with the main objective to improve understanding of horizontal well inflow profiles and performance. For this case study, the areas of focus are inflow profile types, production performance and temperature log response. This paper concludes with lessons learned and practical recommendations to be considered for field development.