Mankhanova A.Y.   Turegeldiyeva K.A.   Sadykov R.M.   Zhapbasbayev U.K.   Zolotukhin A.B.   Yazynina I.V.   Shelyago E.V.  

EOR Screening Using Fuzzy Logic and Comparing with the Results of Filtration Experiments (on the Example of One Kazakhstani Oil Field)

Reporter: Mankhanova A.Y.

Most of the active oil fields are in the late stage of production development. In order to increase hydrocarbon production, field life and recovery factor application of enhanced oil recovery (EOR) methods is required. About 3 million barrels per day (3.5% of total world daily oil) is produced through the introduction of EOR [1].
Selection and planning of the EOR methods is a challenging process which requires a complex approach for its implementation, including system studies. It requires deep understanding of geology, geophysics, petrophysics, geological modeling, hydrodynamic simulation etc.
The essence of the EOR screening is analytical and numerical analysis of diverse information.  EOR screening aims to describe the behavior of the field and evaluate applicability of the EOR methods to ensure selection of the most effective solutions for oil production.
This paper describes the algorithm for EOR methods selection and evaluation based on the analysis of geological and physical characteristics of the field using fuzzy logic method. Fuzzy logic allows effectively applying the proposed method and mitigating risks when selecting the optimal EOR at uncertainty conditions of input information. The results of study were tested in laboratory filtration experiments on the viscous oil displacement (figure 1).

Figure 1. Change of displacement ratio and pressure drop during water injection at a constant rate and different temperature

The aim of the research was to determine the most effective enhanced oil recovery method in terms of displacement efficiency and EOR screening. Laboratory experiments include the base case (water injection); thermal treatment by hot water injection; polymer flooding; polymer flooding at high temperature [2]. This affords to receive results for different reservoir stimulation scenarios. Fuzzy logic method is used to compare and confirm laboratory results.
EOR screening considered more than ten EOR methods including water flooding, hot water injection and polymer flooding which were also tested during laboratory filtration experiments. Both EOR screening and filtration experiments results prove effectiveness of using thermal EOR methods on the studied field.
References
1 ConocoPhillips report “Heavy” oil production technology”, Eurasian Energy Forum KazEnergy, 2008
2 A.E. Mankhanova, Y.K. Ogay, A.B. Zolotukhin, U.K. Zhapbasbayev, "Selection of the Effective Enhanced Oil Recovery Method for Highly Viscous Oil Fields on the Basis of Filtration Experiments (on the Example of One Kazakhstani Field)," SPE Annual Caspian Technical Conference and Exhibition held in Astana, Kazakhstan, 12–14 November 2014.