Integration of Surface and Subsurface Data With New Technologies to Enhance Reservoir Knowledge in Mesozoic Fractured Carbonates Analogues of Mexico

Abstract

Abstract

Naturally fractured carbonates account for about 85% of the total world's carbonate reservoirs. In Mexico, the majority of hydrocarbon production comes from naturally fractured Mesozoic carbonate reservoirs, which also outcrop to the south in the Sierra de Chiapas. Fractures can enhance reservoir permeability but can also act as a barrier for fluid circulation if cementation occurs. Understanding how fractures affect reservoirs needs the integration of multisource surface and subsurface data and techniques. Structural, geological and sedimentological information from outcrop and satellite imaging, integrated with subsurface data and reservoir characterisation workflows help to reduce subsurface uncertainties in fracture analysis. We propose an integrated workflow for reservoir characterisation studies divided into six phases: 1) High resolution satellite structural and fracture modelling to assist in the reduction of uncertainties in a Discrete Fracture Network (DFN) model. The model provides analogue data to compare and enrich attribute analysis in the seismic reservoir domain; 2) Geological interpretation through fieldwork and laboratory data analysis to characterize fractured carbonate outcrops. Automated Mineralogy Analysis (AMA) of sampled units is integrated in the Reservoir Characterisation model; 3) Study of selected Mesozoic carbonate outcrops to understand the stress regime, kinematics, nature and heterogeneity of fracture networks as well as to definite structure timing in relation to oil/gas migration; 3) Deterministic and stochastic fracture modelling approach to produce 3D fracture networks based on well logs, core analysis and outcrop studies; 4) Integration of petrophysical, core analysis, image and well log interpretations into reservoir properties to constrain seismic attributes; 5) Seismic inversion and seismic fracture analysis to highlight fracture density and direction; 6) Interpretation and integration of data into a Reservoir Characterisation Model combining geology, fracture orientation and volumes, cementation, porosity and connectivity.

Fracture, reservoir and facies modelling in the seismic domain is a challenging exercise due to quality and resolution, but the integration of all these techniques with a thorough model of surface fracture network, helps to reduce reservoir uncertainties and improve exploration success, field development planning and production performance.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016