Temperature effects on rock engineering properties and rock-fluid chemistry in opal-CT-bearing chalk

Minde, Mona Wetrhus; Wen-xia, Wang; Madland, Merete Vadla; Zimmermann, Udo; Korsnes, Reidar Inge; Bertolino, S.; Andersen, Pål Østebø

doi:10.1016/j.petrol.2018.05.072

Cited by 44 publications

(43 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, higher temperature intensifies the rock interactions with the injection brine. 7,19,23,24,30,35 Creep conditions did not seem to override the permeability gain during fracturing. This is in agreement with other studies 3,6 that observed a low permeability decline in deviatoric conditions.…”

Section: Discussionmentioning

confidence: 88%

Permeability Evolution of Shear Failing Chalk Cores under Thermochemical Influence

Kallesten¹,

Madland²,

Korsnes³

et al. 2019

IOR 2019 – 20th European Symposium on Improved Oil Recovery

View full text Add to dashboard Cite

Development of petroleum reservoirs, including primary depletion of the pore pressure and repressurization during water injection naturally, leads to changes in effective stresses of the formations. These changes impose mechanical deformation of the rock mass with subsequent altering of its petrophysical properties. Besides mechanical compaction, chalk reservoirs on the Norwegian Continental Shelf also seem susceptible to mineralogical and textural changes as an effect of the injecting fluid's chemical composition and temperature. Understanding such chemical and thermal effects and how they interplay with the mechanical response to changes in effective stresses could contribute to improved prediction of permeability development during field life. This article presents results from mechanical testing of chalk cores of medium-porosity (32%) outcrop chalk (Niobrara Formation, Kansas) in triaxial cells. The experimental setup allows systematic combinations of fluctuating deviatoric stress, temperature (50 and 130°C), and injecting fluid (calcite-equilibrated sodium chloride, calcite-equilibrated sodium sulfate, and reactive synthetic seawater) intended to replicate in situ processes, relevant to the North Sea chalk reservoirs. Deviatoric loading above yield resulted in a shear failure with a steeply dipping fracture of the core and a simultaneous increase in permeability. This occurred regardless of the brine composition. The second and third deviatoric loadings above yield did not have the same strong effect on permeability. During creep and unloading, the permeability changes were minor such that the end permeability remained higher than the initial values. However, sodium sulfate-injected cores retained most of the permeability gain after shear fracturing compared to sodium chloride and synthetic seawater series at both temperatures. Synthetic seawater-injected cores registered the most permeability loss compared to the other brines at 130°C. The results indicate that repulsive forces generated by sulfate adsorption contribute to maintain the fracture permeability.

show abstract

Section: Discussionmentioning

confidence: 88%

Permeability Evolution of Shear Failing Chalk Cores under Thermochemical Influence

Kallesten¹,

Madland²,

Korsnes³

et al. 2019

IOR 2019 – 20th European Symposium on Improved Oil Recovery

View full text Add to dashboard Cite

show abstract

“…The water weakening effect results from several physico‐chemical processes acting over a short‐ and long‐term period, from few minutes to months (P. Ø. Andersen et al., 2018; Heggheim et al., 2005; Korsnes et al., 2008; Loe et al., 1992; Megawati et al., 2013; Minde et al., 2018; Risnes et al., 2005; Røyne et al., 2015). The triaxial tests reported in the present study are typically short‐term (few hours‐long) experiments carried out at room temperature.…”

Section: Discussionmentioning

confidence: 99%

“…The latter interpretation has been discarded by Risnes et al (2005) that have observed water weakening effect on chalks saturated with two miscible fluids, water and glycol as substitutes for the two immiscible fluids present in reservoirs, brine and oil. Additional chemical processes such as Ca 2+ substitution and calcite and quartz dissolution acting over a long period of time (typically few weeks to months) are considered to promote the water weakening in chalks (Heggheim et al, 2005;Korsnes et al, 2008;Loe et al, 1992;Minde et al, 2018). These chemical processes are enhanced at elevated temperature typically above 100°C (Nermoen et al, 2016).…”

Section: Controlling Factors On the Locus Of Yield Surfacementioning

confidence: 99%

“…Considering clean chalk lithology with a negligible amount of clay and quartz, the yield surface is not static and changes locus depending on four key parameters: porosity, saturating fluid, temperature and rate of deformation. Triaxial tests on intact chalk specimens demonstrated the expansion (i.e., hardening) of the yield surface with decreasing porosity and higher rate of deformation, and its shrinkage (i.e., softening) with increasing water saturation (S w ) and temperature (M. A. Andersen et al., 1992; P. Ø. Andersen et al., 2018; Collin et al., 2002; Havmøller & Foged, 1996; Hickman, 2004; Homand & Shao, 2000; Johnsen et al., 2011; Korsnes et al., 2008; Megawati et al., 2013; Minde et al., 2018; Papamichos et al., 1997; Risnes & Flaageng, 1999; Risnes et al., 1998, 2005; Schroeder et al., 1998). The large majority of previous studies were conducted on outcrop chalk, thereby limiting applicability of the results to the deep subsurface chalks.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea

et al. 2021

View full text Add to dashboard Cite

show abstract

“…To a certain extent, with increasing temperature, the behavior of rock salt changes from showing brittleness to toughness. Reference [16], in a study of the effect of temperature on the engineering properties and fluid chemistry of chalk rocks containing opal, confirmed that in a brine-rock system, the temperature and original composition (mineralogy) are the active factors controlling chemical-mechanical interactions. Reference [17], based on the influence of temperature on the elastic constants of anisotropic rocks, found that an increase in temperature could lead to a decrease in the orthogonal constant.…”

Section: Introductionmentioning

confidence: 91%

Effects of Different Temperatures on the Softening of Red-Bed Sandstone in Turbulent Flow

Liu

Cui

et al. 2019

JMSE

View full text Add to dashboard Cite

The rates of chemical reactions are highly dependent on temperature, meaning that the actual geological rock mass is affected by different temperatures. Only when the temperature effect is considered can the mechanism of the influence of temperature on the interaction between water and rock be further understood. It was found that the condition of turbulent flow is more likely to promote the softening of red-bed sandstone than the conditions of laminar flow and static water in an experimental study on the softening effects of different flow patterns on red-bed sandstone. Therefore, based on a multi-functional self-circulating open channel hydraulic test system, this paper designs and completes equal volume saturated tests of red-bed sandstone at low temperature (1 °C), medium temperature (23 °C), and high temperature (45 °C) under the turbulent conditions of three equal temperature gradients. The chemical action of the circulating solution in water flow at different temperatures, the propagation of micro-cracks in rock and the changes in mechanical indexes are discussed. The influence laws and mechanisms of the different temperatures on the softening of red-bed sandstone in turbulent flow are revealed. The results show that low-temperature flow can inhibit the softening of red-bed sandstone in the range of 1–45 °C. With the increase in water flow temperature, the development degrees of micro-structures and the mechanical damage of the corresponding rock become more notable. That is, temperature affects the physical and chemical water–rock interactions and then changes the internal structure of rock, thus affecting the softening and failure processes of red-bed sandstone. The study provides a theoretical basis for the further investigation of the softening laws and mechanisms of other red layered soft rocks by temperature under turbulent conditions.

show abstract

Temperature effects on rock engineering properties and rock-fluid chemistry in opal-CT-bearing chalk

Cited by 44 publications

References 31 publications

Permeability Evolution of Shear Failing Chalk Cores under Thermochemical Influence

Permeability Evolution of Shear Failing Chalk Cores under Thermochemical Influence

Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea

Effects of Different Temperatures on the Softening of Red-Bed Sandstone in Turbulent Flow

Contact Info

Product

Resources

About