A Novel Energy Lifting Approach Using J-Function and Flow Zone Indicator for Oil Fields

M N Tarhuni,M Z Jaafar,W R Sulaiman,K M Sabil

doi:10.32604/ee.2022.017820

Abstract

The X field is located in the southwestern part of block NX89 of Kentan Basin in Libya. This field is produced from Hailan multilayer consolidated sandstone with moderate rock property and a relatively low energy supplying. The reserve of subsurface energy sources is declining with years. Therefore, techniques were combined to achieve the energy optimization and increase hydrocarbon recovery. In order to understand the subsurface formation of the reservoir and facilitate oil production, global hydraulic element technique was used to quantify the reservoir rock types. In addition, stratigraphic modified Lorenz plot was used for reservoir layering. Reservoir heterogeneity was identified using stratigraphic modified Lorenz plot and Dykstra-Parsons coefficient. Leverett J-function was used to average the 13 capillary pressure curves into four main curves to represent the whole reservoir based on flow zone indicator values. Capillary pressure was calculated and plotted with normalized water saturation; a single average curve was defined to represent the rest of the curves. Water saturation was calculated using single and multiple J-functions and compared with the available logs. With multiple J-functions, the matching results were good for both high and low-quality layers, whereas using a single J-function, the match was poor, especially for low FZI layers such as H4c and H6a. Four rock types were identified for this reservoir ranging from medium to good reservoir quality and six different layers were obtained. The reservoir was heterogeneous with a Lorenz coefficient value of approximately 0.72 and a Dykstra-Parsons value of 0.70. All approaches used in this paper were validated and showed improved hydrocarbon recovery factor.

Highlights

The success of several energy engineering operations is highly dependent on petrophysical rock typing [1]
Two techniques are used in the rock selection for modeling and energy studies: these techniques are known as routinely defined rock types Routine Core Analysis (RCAL) and Special Core Analysis (SCAL)
Identifying rock types was useful for determining capillary pressure curves for each facies, making the simulation model less complex, more accurate, and producing better energy outcomes

Summary

Introduction

The success of several energy engineering operations is highly dependent on petrophysical rock typing [1]. Two techniques are used in the rock selection for modeling and energy studies: these techniques are known as routinely defined rock types Routine Core Analysis (RCAL) and Special Core Analysis (SCAL). Identifying regions with similar features (definable and statistically predictable properties) for better characterization and modeling of reservoirs is known as rock typing [2]. The petrophysical rock typing approach has been widely applied in drilling to predict the high fluid loss zones and in production to locate perforations, define potential high energy zones, and design diversion systems in acidizing [8,9]. Petrophysical rock typing has been used in many energy studies (e.g., net-pay cut-off definition) [10] and predicting the permeability of un-cored reservoirs [11–13]. The most significant energy engineering applications that can directly impact the simulation models output and their reliability are representative sample selection for SCAL tests by reducing the number of required representative samples [1,4,14,15] and determining saturation functions for static/dynamic reservoir modeling [2]

Methods

Results

Conclusion