Improvement of the performance of low-salinity water flooding on oil recovery for sandstone reservoirs in Northern Afghanistan Kashkari oil field

Title : Improvement of the performance of low-salinity water flooding on oil recovery for sandstone reservoirs in Northern Afghanistan Kashkari oil field

Abstract:

Low-salinity water flooding (LSWF) is an environmental-friendly enhanced oil recovery (EOR) technique and operates similarly to conventional water flooding without synthetic chemical material. The main mechanism of oil recovery by LSWF is to increase the water wettability in oil reservoirs. In this study, we investigate the effect of the injection patterns on the performance of LSWF in sandstone reservoirs in the Kashkari oil field using a laboratory core flooding test and a numerical simulation. Kashkari oil field is an onshore located in the northern Afghanistan, and currently only the primary recovery method is applied. Therefore, it is important to confirm the effect of low-salinity water injection in the target reservoirs and define an effective injection pattern. Firstly, the core flooding test was conducted to observe the oil recovery effect under the conditions designed to mimic those of the target reservoirs. The effects of LSWF on oil recovery were observed using sandstone cores containing kaolinite in various injection patterns such as secondary recovery mode, tertiary recovery mode, and continuous injection of low-salinity water with different salinity concentrations. In addition, based on changes in ion concentration and pH in the effluent in the core flooding test, it was suggested that the dominant mechanism to improve oil recovery is multiple ion exchange (MIE). Next, core-scale simulations of LSWF based on the MIE were performed and compared with the core flooding results. Finally, the LSWF model based on the MIE was applied to the Kashkari reservoir model to estimate the total amount of recoverable oil. As a result, an amount of 10.3 MMbbls, which is about 7.5% of the field, was produced.

Audience Take Away:

• The effect and mechanism of oil recovery by low-salinity water flooding for sandstone reservoirs using a laboratory core flooding test
• Core-scale numerical simulation of low-salinity water flooding based on multiple ion exchange and comparison with experimental results
• Prediction of oil production rate using the Kashkari reservoir model when changing the injection pattern of low-salinity water

Biography:

Kazunori Abe studied material engineering at Akita Prefectural University, Japan and graduated as M.Sc. in 2010 and Ph.D. in 2013. He then joined the energy resources engineering laboratory of Prof. Hikari Fujii at Akita University, Japan as a postdoctoral fellow. Three years later, he obtained the position of an Assistant Professor at Akita University in 2016, where he now studies oil/gas recovery techniques.