Integrating Reservoir Modelling, High-Precision Temperature Logging and Spectral Noise Logging for Waterflood Analysis

Abstract

Today, geological and hydrodynamic models are widely used for efficient development and monitoring of oil and gas fields. These models are designed to handle a wide range of tasks. Their reliability directly affects the quality of results and any uncertainties should, therefore, be minimised. The use of additional techniques can enhance the reliability and predictive ability of the models and minimise risks. This paper describes how integrating accurate description of flow geometry with reservoir properties and reservoir models to achieve this objective and, to generate a more reliable picture of the reservoir performance. The study included running HPT-PLT-SNL high precision logging tools, and covered a pilot area with five wells in a Cretaceous carbonate reservoir. The wells were completed in the lower and tighter Sub-reservoirs units F1 and F2 and the objective of this pilot is to identify the flow geometry in wells' neighborhood, particularly identify channeling, fracture flows or other types of communication.  The objective of the associated simulations and study is to correlate the acquired and interpreted data with those suggested by simulations and come up with consistent description of reservoir flow geometry within the pilot pattern.

The most challenging point of this flooding campaign is the complexity of the reservoir in this area.  The flooding pilot sets the targets for tight Sub-reservoir carbonates Unit F1 and Unit F2.  It's important to know if the flow ensues exactly within these units and does not communicate with other reservoirs with better permeability.

Objective Description

The subject study, Abu Dhabi's Cretaceous carbonate reservoir is combined of five sub reservoirs and they are as shown in figure 1 below, Units F5, F4, F3, F2 and F1.  All five sub-reservoirs are of different characteristics in terms of permeability, porosity, rock type, etc. (As shown in Table 1 and Fig. 1).   Those sub-reservoirs are lying on top of each others almost without any barriers between them; accordingly, this might provoke the water/gas to cone/slump to/from the concerned reservoirs.

A project is in progress to decide on the development of the tight reservoir (F1+F2) to further improve the poor sweep efficiency, increase the oil recovery in both reservoirs, water slumping, inefficient flank pressure support, vertical permeability between sub-reservoirs, assess the impact of injecting in Units F1+F2 on fluxes across Units F3, F4, F5 and F1 and F2, determine pressure support due to injection in Units F1 and F2, and overlying units.