58 research outputs found
Laboratory experiment based permeability reduction estimation for enhanced oil recovery
No full textFormation damage is an unwanted operational problem-taking place through
several phases of oil reservoir life. The permeability reduction is a key indicator
for the formation damage. Suitable assessment of permeability reduction is
critical for hydrocarbon recovery. As oil production reach tertiary recovery stage
in many fields, formation damage critical evaluation is needed to avoid additional
operational cost and technical feasibility concern. The interaction between
reservoir minerals and chemical injection practices is not fully understood. Also,
clay mineral presence is highly sensitive to the chemicals, while adsorption
phenomena can also occur. The degree of permeability reduction cannot be
generalized for core/field scalestherefore investigating the permeability
reduction in core scale is important before field-scale assessment. Therefore, this
study investigates the permeability reduction after chemicals injection under low
flow rate in sand-quartz cores and in the presence of kaolinite. Artificial
sandpacks were used to control the sand-kaolinite mixture percentage. The
permeability was measured before and after each flood by pressure drop
calculation. The study showed that the seawater flood has the highest reduction
in permeability followed by polymer and surfactants. Also, the results showed a
strong effect of surfactant nature and molecular weight on the adsorption process
and consequently the permeability reduction. The study provides an insight for
the effect of chemicals on cores physical properties
Lignin as per flush reducing gemini surfactant adsorption on clay minerals
Full text linkIn order to increase the oil recovery factor, enhanced oil recovery method has been used to exploit residual oil from the reservoirs. Chemical enhanced oil recovery is one of the proven useful techniques which include injection of surfactant to reduce the oil-water interfacial tension. Recently, the applicability of surfactant to tolerate high salinity and high temperature conditions has resulted in investigation of the new proposed surfactant called aerosol-OT. In this study, the role of clay mineral on aerosol-OT surfactant adsorption, the effect of mineralogical composition and clay mineral percentage on the surfactant adsorption and the effect of salinity and temperature on the adsorption quantity were investigated. Finally, the study examines the effectiveness of alkali lignin as a sacrificial agent for reducing aerosol- OT dynamic adsorption. The experiments were divided into three parts including static adsorption batch experiments, dynamic adsorption in sandpack flood and dynamic adsorption after preflush using alkali lignin. Results of static tests showed that aerosol-OT adsorbed on both sand and clay minerals. Increasing the clay percentage resulted in increase the adsorption, while the increases in temperature reduced the adsorption. The results of adsorption test revealed that the highest adsorption was on kaolinite while the adsorption on illite and montmorillonite surface was significant and should not be ignored. Meanwhile, the adsorption reached its highest value (21 g/kg) in salinity of 60,000 ppm sodium chloride at 25 °C. The dynamic adsorption results showed higher adsorption compared to the static adsorption under the same condition while the increasing trend order remained the same. The maximum adsorption at the dynamic condition was 44 g/kg at the 7% kaolinite sandpack. The alkali lignin was effective to reduce the aerosol-OT adsorption between 25% up to 65% during the dynamic flow. The findings of this study are useful to understand the aerosol-OT adsorption at the reservoir condition and the lignin efficiency as sacrificial agent in reducing aerosol-OT adsorption for further usage in chemical enhanced oil recovery application
Study of sulfosuccinate and extended sulfated sodium surfactants on the Malaysian crude/water properties for ASP application in limestone
No full textAmong the successful methods in enhanced oil recovery (EOR) is the chemical EOR. The surfactant-based chemical techniques are highly recommended. However, some drawbacks remained unsolved such as surfactant selection and application in the reservoirs. Surfactants are particularly applied in sandstone reservoirs, so paving the path to expand the implementation to limestone reservoirs is required. Recently, alkaline surfactant polymer (ASP) was suggested for limestone reservoirs in Malaysia. However, limited studies discussed the effect of surfactant screening on the process. Thus, this study investigates the influence of sulfosuccinate and extended sulfated sodium surfactants in improving ASP performance. The evaluation considered the interfacial tension, wettability and recovery factor. The approach used was two-stage experiments of surfactant analysis and ASP core flooding. The first step used the drop Kruss spinning drop tensiometer, and data physics equipment drop shape analyzer to analyze the IFT and the contact angle. The second stage included the limestone sandpack preparation and characterization, followed by ASP flooding. The results showed that single surfactant has low IFT between 0.005 and 0.05 mN/m, while significantly, the synergy of surfactant mixtures has ultra-low IFT of 0.0006–0.001 mN/m. The contact angle results showed a drastic alteration of 65–81% reduction. The cationic surfactants achieved complete water-wet on limestone. The sandpack preparation confirmed acceptable uniformity by the histogram identification. The oil recovery proved additional recovery between 22 and 40%. The results of this research are a step forward to attain the technical feasibility of ASP in limestone reservoirs
Utilizing Ultrasonic Waves in the Investigation of Contact Stresses, Areas, and Embedment of Spheres in Manufactured Materials Replicating Proppants and Brittle Rocks
Full text linkPeer reviewe
UTILIZING ULTRASONIC WAVES IN THE INVESTIGATION OF CONTACT STRESSES, AREAS, AND EMBEDMENT OF SPHERES IN MANUFACTURED MATERIALS REPLICATING PROPPANTS AND BRITTLE ROCKS
Full text linkIn the oil and gas industry, hydraulic fracturing (HF) is a common application to create additional permeability in unconventional reservoirs. Using proppant in HF requires understanding the interactions with rocks such as shale, and the mechanical
aspects of their contacts. However, these studies are limited in literature and inconclusive. Therefore, the current research aims
to apply a novel method, mainly ultrasound, to investigate the proppant embedment phenomena for different rocks. The study
used proppant materials that are susceptible to fractures (glass) and others that are hard and do not break (steel). Additionally,
the materials used to represent brittle shale rocks (polycarbonate and phenolic) were based on the ratio of elastic modulus
to yield strength (E/Y). A combination of experimental and numerical modeling was used to investigate the contact stresses,
deformation, and vertical displacement. The results showed that the relation between the stresses and ultrasound reflection
coefficient follows a power-law equation, which validated the method application. From the experiments, plastic deformation
was encountered in phenolic surfaces despite the corresponding contacted material. Also, the phenolic stresses showed a
difference compared to polycarbonate for both high and low loads, which is explained by the high attenuation coefficient of
phenolic that limited the quality of the reflected signal. The extent of vertical displacements surrounding the contact zone
was greater for the polycarbonate materials due to the lower E/Y, while the phenolic material was limited to smaller areas not
exceeding 50% of polycarbonate for all tested load conditions. Therefore, the study confirms that part of the contact energy
in phenolic material was dissipated in the plastic deformation, indicating greater proppant embedment, and leading to a loss
in fracture conductivity for rocks of higher E/
Evaluation of Flaxseed Hydrocolloid’s Potential in Improving Oil Recovery
No full textThe use of natural materials to improve oil recovery and production is believed to be a suitable method. The current study examined hydrocolloids extracted from flaxseed as a viscosifying agent for improved and enhanced oil recovery EOR. It aimed to investigate the effect of concentration, temperature, salinity, and ageing time on the rheology of the flaxseed gel solution (FGS). The study also highlighted the solution’s performance at the core level for carbonate reservoirs. The FGS was successfully extracted by soaking and heating at 70 °C. Fourier-transform infrared (FTIR) spectroscopy results showed polysaccharide dominance in the mucilage. The rheology outcomes showed that the FGS was able to increase the water viscosity by 5–17 cp at 25 °C. Different concentrations of the FGS preserved its viscosity at temperatures of 25–45 °C. The salinity reduced the gel’s viscosity, especially above 2.5 wt%. A 50 g/L solution successfully tolerated all the tested salinities and the temperature range at all shear rates. A reduction in viscosity was observed during the first five days of ageing due to biological degradation caused by bacteria. Ageing had no major influence between 5 and 10 days. The FGS resulted in a 12 % incremental oil recovery. The sweep efficiency improved due to the 84 % mobility enhancement. This study confirms the possibility of deploying hydrocolloids as a natural viscosifier to improve the oil recovery in Kazakhstan’s oil reservoir conditions
COMPARATIVE STUDY OF NATURAL CHEMICAL FOR ENHANCED OIL RECOVERY: FOCUS ON EXTRACTION AND ADSORPTION AT QUARTZ SAND SURFACE
Full text linkIn chemical enhanced oil recovery (CEOR), it is very important to utilize the excessive usage of chemicals. A great opportunity lies in adopting natural surfactants, since it is cheaper, ecosystem friendly, and less toxic than their counterpart synthetic surfactants. Despite the availability of natural surfactant sources, it is yet very early to decide on their applicability. Therefore, this research focuses on natural-saponin extracted from different raw materials available in the Middle East and their interaction with quartz-sand. A special focus was given to the adsorption isotherm models to describe the interaction with the reservoir rocks
Numerical Simulation of Flaxseed Gum Potential in Improving Oil Recovery:Focus on Offshore Kazakhstan
No full textEnhanced oil recovery (EOR) entails modifying the water-oil composition in the process of recovering oil (Charoentanaworakun et al., 2023, El-Masry et al., 2023). One of the main techniques is the injection of chemicals to increase oil recovery. This method is crucial to extract trapped oil from mature oilfields, increasing their effectiveness and lengthening their lifespan. One reason for the rise in water viscosity can be attributed to certain substances, including high molecular weight polymers, gels, and composites that undergo in-situ cross-linking, which can cause this effect. Increasing water viscosity can technically reduce water mobility, leading to better sweep efficiency (Arshad and Harwell, 1985, Abbas et al., 2020) Chemical EOR techniques improve oil recovery by modifying the injected water phase by changing the reservoir's fluid-fluid and/or fluid-rock interactions. Chemical Enhanced Oil Recovery (CEOR) methods utilize a chemical mixture as the displacing agent, which prompts an increase in the capillary number or reduction in the mobility ratio. The primary goal of chemical EOR procedures is to affect one of the following variables: mobility (by utilizing polymer solutions with increased viscosity), rock wettability, and interfacial tension between two immiscible phases (by applying surfactants or alkalis to the displacing fluid). The suitability of the chemical as a recovery enhancer is evaluated via the following parameters: it should enhance the viscosity of water while allowing it to flow through porous media and displacing more hydrocarbons; it should be functional for a reasonable duration of time without degradation; inhibit water fingering and manage the front pattern. Therefore, discovering such chemicals is supported by rheological characterization at various salinities, temperatures, and chemical concentrations. While the primary phase is comparable to the subsurface settings, it demands a meticulous evaluation of the flow behavior during dynamic flooding (Druetta and Picchioni, 2020). Despite their efficiency and low cost, most of the chemicals harm the environment, which increases the focus on developing eco-friendly chemicals that can effectively replace commonly used polymers like hydrolysis polyacrylamide (HPAM). This has led to the exploration of various natural polymers such as Arabic gum, Xanthan Gum, and Guar Gum, with encouraging results as shown by the research conducted by Saha et al. (2019) and Dessbesell et al. (2020). However, one major challenge in their widespread application is their accessibility and ability to endure diverse reservoir conditions such as temperature and salinity, as highlighted in Bento and Moreno's (2016) study. Despite the potential of these natural gums, the industry still needs to improve its implementation process, and some valuable sources of natural materials have not yet been fully developed.</p
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