Effects of cleaning process using toluene and acetone on water-wet-quartz/CO2 and oil-wet-quartz/CO2 wettability

Al-Yaseri, Ahmed; Abbasi, Ghazanfer Raza; Yekeen, Nurudeen; Al‐Shajalee, Faaiz; Giwelli, Ausama; Xie, Quan

doi:10.1016/j.petrol.2021.109555

Cited by 28 publications

(21 citation statements)

References 70 publications

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“…Solvents (toluene and alcohol) were used to clean the core plugs and prepare them for the measurements. Toluene was used to clean any residual oil in the rocks while alcohol was used to remove precipitated salt within the rock's pores (Al-Yaseri et al 2022;Isah et al 2021a, b).…”

Section: Samples Preparationmentioning

confidence: 99%

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Alameedy

Alhaleem

Isah

et al. 2022

J Petrol Explor Prod Technol

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Acidizing is one of the most used stimulation techniques in the petroleum industry. Several reports have been issued on the difficulties encountered during the stimulation operation of the Ahdeb oil field, particularly in the development of the Mishrif reservoir, including the following: (1) high injection pressures make it difficult to inject acid into the reservoir formation, and (2) only a few acid jobs have been effective in Ahdeb oil wells, while the bulk of the others has been unsuccessful. The significant failure rate of oil well stimulation in this deposit necessitates more investigations. Thus, we carried out this experimental study to systematically investigate the influence of acid treatment on the geomechanical properties of Mi4 formation of the Mishrif reservoir. The acid core-flood experiments were performed on seven core samples from the oil reservoir in central Iraq. The porosity, permeability, acoustic velocities, rock strength, and dynamic elastic parameters were computed before and after the acidizing treatment. To determine the optimal acid injection rate, different injection flow rates were used in the core-flooding experiments. The propagation of an acid-induced wormhole and its effect on the rock properties were analyzed and compared to that of intact rocks. Computed tomography (CT) scan and a 3D reconstruction technique were also conducted to establish the size and geometry of the generated wormhole. To analyze the influence of mineralogical variation and heterogeneity and confirm the consistency of the outcomes, acidizing experiments on different rock samples were conducted. The results demonstrate that for all the rock samples studied, the mechanical properties exhibit rock weakening post-acid treatment. The Young’s modulus reduced by 26% to 37%, while the Poisson’s ratio, the coefficient of lateral earth pressure at rest, and the material index increased by 13% to 20%, 23% to 32%, and 28% to 125%, respectively. The CT scan visually confirmed that the acid treatment effectively creates a pathway for fluid flow through the core.

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Section: Samples Preparationmentioning

confidence: 99%

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Alameedy

Alhaleem

Isah

et al. 2022

J Petrol Explor Prod Technol

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“…A total of five observation points with three repeats were obtained for the electrical resistivity measurements. The error in contact angle measurements was ±3° . The average standard deviation for the resistivity index (RI), rock resistivity ( R t ), and formation factor ( F ) were 5.34, 8.29 Ω·m, and 16.06, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…The error in contact angle measurements was ±3°. 77 The average standard deviation for the resistivity index (RI), rock resistivity (R t ), and formation factor (F) .06, respectively. We used the twoelectrode (silver chloride-coated silver electrodes) configuration.…”

Section: Sample Preparation Two Cylindrical Homogeneousmentioning

confidence: 99%

Effect of Rock Wettability on the Electric Resistivity of Hydrate Formations: An Experimental Investigation

et al. 2021

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Gas hydrates are large energy resources with estimated global reserves of approximately 500–10 000 Gt of carbon, which can be extracted from underground reservoirs. In addition, such reservoirs can potentially catastrophically release greenhouse gases (such as methane or carbon dioxide). Classically, rock wettability is one of the key factors in predicting fluid flow behavior, fluid distribution, reserves, and productivities. However, the effect of wettability on the electric resistivity of hydrate formations is poorly understood. Thus, to evaluate the influence of rock wettability on the electrical resistivity (note that resistivity logging is a key well logging tool) of hydrate-bearing sandstone, nuclear magnetic resonance experiments were conducted. Clearly, the effective porosity and liquid saturation increased with increasing temperature, due to hydrate dissociation. Furthermore, the resistivity index and rock resistivity (R t) increased with increasing hydrate saturation, and the formation factor demonstrated a positive correlation with hydrate saturation, though the formation factor for oil-wet (OW) sandstone was higher than that for water-wet (WW) sandstone. This work will thus significantly improve the fundamental understanding of the petrophysical properties of gas hydrate reservoirs so that energy production can be optimized, geohazards can be avoided, and the hydrate gun hypothesis can be better assessed.

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“…First, the shale core specimens were trimmed into specific dimensions (1 cm width × 1.5 cm length × 1 cm height) that can conveniently fit into the moving table, and the cut shale specimens were polished to achieve an even surface. Acetone was used to clean the shale surfaces . Then, the shale substrate was positioned on the moving table in the view cell of the Krüss drop shape analyzer 100 (Eurotechnica, Germany), and temperature was increased gradually at 10 °C until the desired temperature was reached.…”

Section: Methodsmentioning

confidence: 99%

“…Acetone was used to clean the shale surfaces. 51 Then, the shale substrate was positioned on the moving table in the view cell of the Kruss drop shape analyzer 100 (Eurotechnica, Germany), and temperature was increased gradually at 10 °C until the desired temperature was reached.…”

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confidence: 99%

Experimental Assessment of Fracture Initiation and Wettability in Low and High Brittle Shales by CO₂ Foam Fracturing Fluids

et al. 2022

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CO2 foam fracturing fluid has received significant attention because of its versatility in water-sensitive formations. However, the mechanisms of hydraulic fracturing of shale reservoirs by CO2 foam fracking fluid, in terms of fracture initiation and propagation remain unclear. In this paper, an experimental study was conducted to correlate the fluid interaction and fracture propagation in various shale formations having brittleness indices of 0.43, 0.50, and 0.74 to the rock-fracking fluid wettability. The shale wetting state in the presence of the CO2 foam fracturing fluid was determined from contact angle measurements through the Krüss drop shape analyzer (DSA 100), and the hydraulic fracturing was conducted via a tri-axial fracking system. A specific concentration of polyacrylamide (500 ppm) is used as a drag-reducing agent and selected for the hydraulic fracturing experiments. CO2 foam fracturing resulted in low fracture initiation pressure in the shale, having a high brittleness index of 0.74 BIm, and it remains the same at high temperatures. The length and aperture of the hydraulic fracture were then correlated with fracturing fluid–shale contact angles. The Mancos shale is sand-rich (with 21 wt % calcite and 52 wt % quartz), and it remained strongly water-wet on the interaction with the fracking fluid, and the net breakdown pressure was found to be lower in the fracturing tests of the Mancos shale. The Marcellus shale (with 31 wt % calcite and 22 wt % quartz) was intermediately wet (with a contact angle of 93.1°), whereas the Eagle Ford shale with high clay content (77 wt % calcite and 11 wt % quartz) was CO2-wet (with a contact angle of 109°) at 80 °C. Marcellus and Eagle Ford shales demonstrated higher fracture initiation pressures during the fracking experiments than the Mancos shale. The study suggests that fracking fluid–shale wettability has an essential role in the fracking of shale formations and should be considered in optimizing hydraulic fracturing fluid.

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Effects of cleaning process using toluene and acetone on water-wet-quartz/CO2 and oil-wet-quartz/CO2 wettability

Cited by 28 publications

References 70 publications

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Effect of Rock Wettability on the Electric Resistivity of Hydrate Formations: An Experimental Investigation

Experimental Assessment of Fracture Initiation and Wettability in Low and High Brittle Shales by CO₂ Foam Fracturing Fluids

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Effects of cleaning process using toluene and acetone on water-wet-quartz/CO2 and oil-wet-quartz/CO2 wettability

Cited by 28 publications

References 70 publications

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Effect of acid treatment on the geomechanical properties of rocks: an experimental investigation in Ahdeb oil field

Effect of Rock Wettability on the Electric Resistivity of Hydrate Formations: An Experimental Investigation

Experimental Assessment of Fracture Initiation and Wettability in Low and High Brittle Shales by CO2 Foam Fracturing Fluids

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Experimental Assessment of Fracture Initiation and Wettability in Low and High Brittle Shales by CO₂ Foam Fracturing Fluids