Using the Link Between Diagenesis and Fracturing to Accurately Predict, Characterize, and Model Fluid-Flow in Fractured Carbonate Rocks (2005)

Using the Link Between Diagenesis and Fracturing to Accurately Predict, Characterize, and Model Fluid-Flow in Fractured Carbonate Rocks Julia F.W. Gale; Julia F.W. Gale U. of Texas at Austin Search for other works by this author on: This Site Google Scholar Stephen E. Laubach; Stephen E. Laubach Bureau of Economic Geology Search for other works by this author on: This Site Google Scholar Jon Edward Olson; Jon Edward Olson U. of Texas at Austin Search for other works by this author on: This Site Google Scholar Randall Marrett Randall Marrett U. of Texas at Austin Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Latin American and Caribbean Petroleum Engineering Conference, Rio de Janeiro, Brazil, June 2005. Paper Number: SPE-97382-MS https://doi.org/10.2118/97382-MS Published: June 20 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Gale, Julia F.W., Laubach, Stephen E., Olson, Jon Edward, and Randall Marrett. "Using the Link Between Diagenesis and Fracturing to Accurately Predict, Characterize, and Model Fluid-Flow in Fractured Carbonate Rocks." Paper presented at the SPE Latin American and Caribbean Petroleum Engineering Conference, Rio de Janeiro, Brazil, June 2005. doi: https://doi.org/10.2118/97382-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Latin America and Caribbean Petroleum Engineering Conference Search Advanced Search AbstractBy taking diagenetic processes into account we improved quantitative fracture population description. Using diagenesis information also allows more accurate geomechanical modeling and creation of more realistic fracture patterns for use in fluid-flow simulation. Mechanical rock properties and fracture attributes change with diagenesis and fracture architecture depends on rock properties (particularly subcritical crack index) at the time of fracturing. Preservation of fracture void space depends on cement precipitation synchronous with fracture opening that obeys systematic rules. The greatest effect on large fractures is from later cements, which are typically heterogeneous in distribution.IntroductionCarbonate reservoirs are important sources of hydrocarbons, and fluid flow within them is commonly influenced by fractures. Yet we currently have limited understanding of processes that govern how fractures form, the relationship between precipitation of natural cement and fracturing, and how fracture patterns and diagenesis interact to control reservoir quality. In this study we used fracture and diagenesis observations and modeling, quantitative fracture population description, geomechanical rock testing and modeling, and a new approach to generating fracture patterns for use in fluid-flow simulation to explore how an appreciation of the links between diagenesis and fracturing in carbonate rocks can enhance hydrocarbon exploration and development success.Previous work on fracturing in carbonates has been wide-ranging in focus1–3 but has not been sufficient to inform realistic flow simulation. Partly this is because fracture network modeling has been inadequate and partly it is because the link between diagenesis and fracturing has not been fully addressed. Gale et al.4 focused on diagenesis and fracturing in dolostones and here we widen the scope to include all carbonate rocks.Fracture patterns were generated using a fracture mechanics based crack growth simulator that can take into account diagenetic effects through time by varying rock and fracture properties. The fracture simulator generates fracture networks with realistic fracture spacing, aperture and length distributions that depend on measurable rock parameters such as Young's modulus, subcritical crack index, mechanical layer thickness and tectonic strain.Structural DiagenesisThe cause and timing of opening-mode fractures cannot be deduced from morphology alone because fractures formed under various loading conditions during burial and exhumation may have similar or identical shapes and are thus superficially alike. Subtle diagenetic features such as crack-seal texture within fractures can help identify the conditions of fracture formation. To fully exploit the fracture information inherent in the byproducts of diagenetic reactions, the sequence of precipitation, dissolution, and mineral reaction events, relative to growth of fractures must be assembled. The term structural diagenesis5 indicates a combination of structural and diagenetic processes associated with mechanical property changes during fracture growth and sealing, and we use this term here. A complex diagenetic sequence is advantageous because it potentially yields more data to indicate the timing of fractures in relation to other events. Better information about fracture timing relative to diagenesis can lead to better predictions of fracture patterns and attributes in the interwellbore region, as will be described. Keywords: fracture growth, fracture pattern, carbonate rock, limestone, dolomite, fracture characterization, hydraulic fracturing, diagenesis, subcritical crack index, upstream oil & gas Subjects: Hydraulic Fracturing, Reservoir Characterization, Faults and fracture characterization This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.