scholarly journals Structural control on fluid flow and shallow diagenesis: insights from calcite cementation along deformation bands in porous sandstones

Solid Earth ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 2169-2195
Author(s):  
Leonardo Del Sole ◽  
Marco Antonellini ◽  
Roger Soliva ◽  
Gregory Ballas ◽  
Fabrizio Balsamo ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Structural Control ◽  
Control Flow ◽  
Porous Rocks ◽  
Deformation Bands ◽  
Seismic Resolution ◽  
Porous Sandstone ◽  
Reservoir Compartmentalization ◽  
Porosity And Permeability ◽  
And Control

Abstract. Porous sandstones are important reservoirs for geofluids. Interaction therein between deformation and cementation during diagenesis is critical since both processes can strongly reduce rock porosity and permeability, deteriorating reservoir quality. Deformation bands and fault-related diagenetic bodies, here called “structural and diagenetic heterogeneities”, affect fluid flow at a range of scales and potentially lead to reservoir compartmentalization, influencing flow buffering and sealing during the production of geofluids. We present two field-based studies from Loiano (northern Apennines, Italy) and Bollène (Provence, France) that elucidate the structural control exerted by deformation bands on fluid flow and diagenesis recorded by calcite nodules associated with the bands. We relied on careful in situ observations through geo-photography, string mapping, and unmanned aerial vehicle (UAV) photography integrated with optical, scanning electron and cathodoluminescence microscopy, and stable isotope (δ13C and δ18O) analysis of nodules cement. In both case studies, one or more sets of deformation bands precede and control selective cement precipitation. Cement texture, cathodoluminescence patterns, and their isotopic composition suggest precipitation from meteoric fluids. In Loiano, deformation bands acted as low-permeability baffles to fluid flow and promoted selective cement precipitation. In Bollène, clusters of deformation bands restricted fluid flow and focused diagenesis to parallel-to-band compartments. Our work shows that deformation bands control flow patterns within a porous sandstone reservoir and this, in turn, affects how diagenetic heterogeneities are distributed within the porous rocks. This information is invaluable to assess the uncertainties in reservoir petrophysical properties, especially where structural and diagenetic heterogeneities are below seismic resolution.

scholarly journals Structural control on fluid flow and shallow diagenesis: Insights from calcite cementation along deformation bands in porous sandstones

2020 ◽  
Author(s):  
Leonardo Del Sole ◽  
Marco Antonellini ◽  
Roger Soliva ◽  
Gregory Ballas ◽  
Fabrizio Balsamo ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Structural Control ◽  
Structural Features ◽  
Nodule Formation ◽  
Low Permeability ◽  
Deformation Bands ◽  
Diagenetic Processes ◽  
Flow Mechanisms ◽  
Reservoir Compartmentalization ◽  
Δ13c And Δ18o

Abstract. Porous sandstones are important reservoirs for geofluids. Interaction therein between deformation and cementation during diagenesis is critical since both processes can strongly reduce rock porosity and permeability, deteriorating reservoir quality. Deformation bands (DBs) and structural-related diagenetic bodies, here named Structural and Diagenetic Heterogeneities (SDH), have been recognized to negatively affect fluid flow at a range of scales and potentially lead to reservoir compartmentalization, influencing flow buffering and sealing during production. The hydraulic behavior of DBs is not yet fully constrained, and it remains poorly understood also how diagenetic processes interact with DBs to steer fluid flow mechanisms and evolution. In this contribution we present two field-based studies from Loiano (Northern Apennines, Italy) and Bollène (Provence, France) that contribute to elucidating the structural control exerted by DBs on fluid flow and diagenesis recorded by calcite nodules associated with the bands. We relied on careful field observations and a variety of multiscalar mapping techniques (photography, string mapping, and drone aerial photography), integrated with optical, scanning electron and cathodoluminescence microscopy, and stable isotope (δ13C and δ18O) analysis of nodules cement. In both case studies, at least one set of DBs precedes and controls selective cement precipitation. Cement texture and cathodoluminescence patterns, and their invariably negative δ13C and δ18O value ranges, suggest a meteoric environment for nodule formation. In Loiano, DBs acted as low-permeability barriers to fluid flow and promoted selective cement precipitation. In Bollène, clusters of DBs restricted fluid flow and focused diagenesis in parallel-to-band compartments. Our work shows how low-permeability DBs in porous sandstones can actually affect fluid flow and localize diagenetic processes (in the shallow crust) that, in turn, could further enhance the sealing capacity of these structural features.

scholarly journals Deformation Bands and Associated FIP Characteristics From High-Porous Triassic Reservoirs in the Tarim Basin, NW China: A Multiscale Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenyuan Yan ◽  
Ming Zha ◽  
Jiangxiu Qu ◽  
Xiujian Ding ◽  
Qinglan Zhang
Keyword(s):  
Thin Section ◽  
Oil And Gas ◽  
Fluid Dynamic ◽  
Shear Bands ◽  
Raman Laser ◽  
Homogenization Temperature ◽  
High Porosity ◽  
Porous Rocks ◽  
Deformation Bands ◽  
Porosity And Permeability

Deformation bands are widely formed and distributed in Triassic high-porous rocks as a result of multistage tectonic movement. In this research, core observation, the rock thin section (fluorescence and casting thin section), FIB-SEM, X-ray diffraction, Raman laser, and thermometry of fluid inclusions were employed to describe the macro- and micro characteristics of deformation bands and their associated relationship with microfractures. Results indicate that the main types of deformation bands formed in the Lunnan Triassic high-porosity sandstone during the Yanshanian and Himalayan periods under different temperature and pressure conditions are compaction shear bands, and their quantity increases evidently with the distance of thrust faults. The density of deformation bands near the fault is about 15/m; porosity and permeability decrease sharply compared with those of the host rock. Microscopically, two obtained fluid-inclusion planes (FIPs) can be distinguished as 51 samples collected from 12 wells by the cutting relationship and mechanical characteristics. The homogenization temperature of associated aqueous inclusion is generally characterized by two peaks, mainly 70–80°C and 110–120°C, which were formed in the Late Yanshanian and Late Himalayan periods. The formation period of deformation bands induced by the intragranular microfractures improved the reservoir seepage capacity. In the later stage, as the interlayer and barrier with low porosity and low permeability affects the distribution of oil and gas, which is an important factor in this study of the local fluid dynamic field and high-quality reservoir evolution distribution.

Can stationary cnoidal waves explain periodic deformation bands in porous sandstone?

2020 ◽  
Author(s):  
Liz Elphick ◽  
Christoph Schrank ◽  
Adelina Lv ◽  
Klaus Regenauer-Lieb
Keyword(s):  
Fluid Flow ◽  
Damage Zone ◽  
Wave Model ◽  
Cnoidal Wave ◽  
Deformation Bands ◽  
Cnoidal Waves ◽  
Compaction Bands ◽  
Weak Phase ◽  
Porous Sandstone ◽  
Non Linear

<p>Deformation bands are sub-seismic brittle structures found in granular materials. These structures exhibit two spatial distributions: [1] non-linear decay of spacing associated with the damage zone of a fault, and [2] periodic, constant spacing not associated with faults. Periodically spaced deformation bands are of interest as they can be pervasive through porous (>5% φ) formations and are known to impact fluid flow. Bands can act as conduits or barriers to fluid flow and are commonly identified in petroleum reservoirs. An understanding of the factors controlling their distribution is therefore of great importance.</p><p>Here, we test a novel mathematical theory postulating that material instabilities in solids with internal mass transfer associated with volumetric deformation are due to elastoviscoplastic p-waves termed cnoidal waves. The stationary cnoidal wave model for periodic compaction bands predicts that their spacing is controlled by important material properties: the permeability of the weak phase in the pores, the viscosity of the weak phase, and the inelastic volumetric viscosity (strength) of the solid grains. A semi-analytical parametric study of the dimensional non-linear governing equations yields a surprisingly simple scaling relationship, which requires testing in the field. Stronger units with higher permeability are predicted to exhibit a wider spacing between deformation bands.</p><p>We test the cnoidal-wave model on natural deformation bands from Castlepoint, North Island, New Zealand. These bands are hosted by Miocene turbidites of the Whakataki formation, which formed in tectonically controlled trench-slope basins associated with the onset of subduction of the Pacific plate beneath the Zealandian plate along the Hikurangi subduction margin. Adjacent sand- and siltstone beds exhibit significant differences in deformation band spacing. Spacing statistics derived from field mapping and laboratory measurements of host-rock permeability and strength are employed to test the scaling relation predicted by the cnoidal wave model. Inconsistencies between theoretical and observed spacing are discussed critically.</p>

scholarly journals Use of Image Correlation to Measure Macroscopic Strains by Hygric Swelling in Sandstone Rocks

2021 ◽  
Vol 11 (6) ◽  
pp. 2495
Author(s):  
Belén Ferrer ◽  
María-Baralida Tomás ◽  
David Mas
Keyword(s):  
Cross Correlation ◽  
Pore Space ◽  
Digital Camera ◽  
Experimental Methods ◽  
Image Correlation ◽  
Rock Surface ◽  
Experimental Setup ◽  
Porous Rocks ◽  
Porous Sandstone ◽  
Variable Displacement

Some materials undergo hygric expansion when soaked. In porous rocks, this effect is enhanced by the pore space, because it allows water to reach every part of its volume and to hydrate most swelling parts. In the vicinity, this enlargement has negative structural consequences as adjacent elements support some compressions or displacements. In this work, we propose a normalized cross-correlation between rock surface texture images to determine the hygric expansion of such materials. We used small porous sandstone samples (11 × 11 × 30 mm3) to measure hygric swelling. The experimental setup comprised an industrial digital camera and a telecentric objective. We took one image every 5 min for 3 h to characterize the whole swelling process. An error analysis of both the mathematical and experimental methods was performed. The results showed that the proposed methodology provided, despite some limitations, reliable hygric swelling information by a non-contact methodology with an accuracy of 1 micron and permitted the deformation in both the vertical and horizontal directions to be explored, which is an advantage over traditional linear variable displacement transformers.

scholarly journals Study on the Influence of Geometric Characteristics of Grain Membranes on Permeability Properties in Porous Sandstone

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 587
Author(s):  
Run Shi ◽  
Huaiguang Xiao ◽  
Chengmeng Shao ◽  
Mingzheng Huang ◽  
Lei He
Keyword(s):  
Fluid Flow ◽  
Single Parameter ◽  
Control Group ◽  
Porous Rock ◽  
Permeability Characteristics ◽  
Natural Rock ◽  
Porous Sandstone ◽  
Novel Method ◽  
Boltzmann Method ◽  
Flow Laws

Studying the influence of grain characteristics on fluid flow in complex porous rock is one of the most important premises to reveal the permeability mechanism. Previous studies have mainly investigated the fluid flow laws in complex rock structures using an uncontrollable one single parameter of natural rock models or oversimplified control group models. In order to solve these problems, this paper proposes a novel method to reconstruct models that can independently control one single parameter of rock grain membranes based on mapping and reverse-mapping ideas. The lattice Boltzmann method is used to analyze the influence of grain parameters (grain radius, space, roundness, orientation, and model resolution) on the permeability characteristics (porosity, connectivity, permeability, flow path, and flow velocity). Results show that the grain radius and space have highly positive and negative correlations with permeability properties. The effect of grain roundness and resolution on permeability properties shows a strong regularity, while grain orientation on permeability properties shows strong randomness. This study is of great significance to reveal the fluid flow laws of natural rock structures.

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