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Collaborating Authors
Dual Application of Polyelectrolyte Complex Nanoparticles as Enzyme Breaker Carriers and Fluid Loss Additives for Fracturing Fluids
Bose, Charles C (The University of Kansas, Lawrence, KS) | Alshatti AIR, Bader (The University of Kansas, Lawrence, KS) | Swarts, Levi (The University of Kansas, Lawrence, KS) | Gupta, Aadish (The University of Kansas, Lawrence, KS) | Barati, Reza (The University of Kansas, Lawrence, KS)
Abstract Guar-based fluids are commonly used as fracturing fluids to form a filter cake, propagate the fracture and carry proppants during a typical hydraulic fracturing job. High viscosity during injection and degradation afterwards are the characteristics of a high quality fracturing fluid that can maintain a highly conductive fracture during production. In order to achieve a conductive fracture, cross-linkers and breakers are added to the fluid. Filter cakes form on the faces of the fracture during injection causing a major pressure drop between the fracture and the reservoir during the production. Degradation of filter cakes formed on fracture faces has been accomplished using chemical breakers Enzymes and oxidizers are the two main classes of breakers. Enzyme breakers have many advantages over chemical oxidizers: they are cheap, are not consumed during their catalytic reaction with guar, react only with the polymer, are environmentally benign, easy to handle and do not damage wellhead equipment. Different methods of injecting high concentration breakers are still not capable of degrading the residues left after the fracturing jobs. Permeability reduction of proppant pack due to gel residues, width loss caused by the unbroken gel on fracture face and length loss caused by incomplete degradation of filter cake near the tip of the fractures have been previously reported. It has been previously proven that polyethylenimine-dextran sulfate (PEI-DS) nanoparticles can delay the release of enzymes which reduce the viscosity of cross linked guar. This delayed release can be advantageous in order to inject higher concentrations of enzymes by encapsulating the enzyme inside nanoparticles. However, performance of these nanoparticles in reaction with high concentration filter cakes has not been studied yet. The main objective of this work is to study the feasibility of using polyelectrolyte complex nanoparticles as enzyme breaker carriers and fluid loss additives to be used for hydraulic fracturing applications. Specifically, the fluid loss prevention and clean-up capabilities of the nanoparticle system for fractures propagated in tight formations are studied. Static fluid loss tests showed a significant reduction, caused by PEC nanoparticles, in both fluid loss coefficients and fluid loss volumes of tight core plugs with permeability values within the 0.01-0.1 mD range. Fracture conductivity tests, both fluid loss and clean-up, were conducted using HPG gel, HPG gel mixed with enzyme, and HPG gel mixed with enzyme-loaded nanoparticle systems and the results were compared with the baseline conductivity of the system. Significant improvement in the retained conductivity of the proppant pack was observed using the enzyme-loaded nanoparticle system.
- Europe (0.66)
- North America > United States > California (0.46)
- North America > United States > Kansas (0.29)
Summary Viscoelastic surfactants (VESs) have been used for acid diversion and fracturing fluids. VESs were introduced because they are less damaging than polymers. VESs' high cost, low thermal stability, and incompatibility with several additives (e.g., corrosion inhibitors) limit their use. The goal of this study is to investigate the interaction of VES micelles with different nanoparticle shapes to reduce VES loadings and enhance their thermal stability. This work examined spherical and rod-shaped nanoparticles of silica and iron oxides. The effects of particle size, shape, and surface charge on a zwitterionic VES micellization were conducted. The physical properties were measured using ζ-potential, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The rheological performances of VES solutions were evaluated at 280 and 350°F using a high-pressure/high-temperature rotational rheometer. The proppant-carrying capacity of the fracturing fluids was evaluated using a high-pressure/high-temperature see-through cell and dynamic oscillatory viscometer. The fluid loss and formation damage were determined using corefloods and computed-tomography scans. The interaction between nanoparticles and VES is strongly dependent on the VES concentration, temperature, nanoparticle characteristics, and concentration. The spherical particles at 7-lbm/1,000 gal loading extended the VES-based-fluid thermal stability at VES loading of 4 wt% up to 350°F. The nanorods effectively enhanced and extended the thermal-stability range of the VES system at VES concentration of only 2 wt%. Both particle shapes performed similarly at 4 wt% VES and 280°F. The addition of silica nanorods extended the thermal stability of the 4 wt% VES aqueous fluid, which resulted in an apparent viscosity of 200 cp for 2 hours. The addition of rod-shaped particles enhanced the micelle to micelle entanglement, especially at VES loading of 2 wt%. The use of nanoparticles enhanced the micelle/micelle networking, boosting the fluid-storage modulus and enhancing the proppant-carrying capacity. The addition of nanoparticles to the VES lowered its fluid-loss rate and minimized formation damage caused by VES-fluid invasion. This research gives guidelines to synthesize nanoparticles to accommodate the chemistry of surfactants for higher-temperature applications. It highlights the importance of the selected nanoparticles on the rheological performance of VES.
- Europe (0.67)
- North America > United States > Texas (0.28)
- North America > United States > Pennsylvania (0.28)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.46)
- Well Drilling > Formation Damage (1.00)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (1.00)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management (1.00)
Abstract The concept of relative viscosity is widely used in literature for describing the rheological behavior of Newtonian and non-Newtonian fluids containing particles. Generally, nanoparticles are used at low concentrations; but Einstein equation hardly predicts the suspension viscosity values. Similarly, equations developed for high particle concentrations hardly made the predictions too. This paper presents the inability of Einstein and Krieger-Dougherty equations in predicting the relative viscosity of surfactant-based fluids (SBF), polymeric fluids, and SBF-polymeric fluid blends. Concentrations of 5% and 33 lb/Mgal guar were used for the laboratory preparation of SBF and polymeric fluids respectively, and both fluids contained 4% potassium chloride (KCl). Also, the mixture of SBF and polymeric fluids in the ratios of 3:1 (vol.) and 1:3 (vol.) resulted into Blend-A and Blend-B fluids respectively. The addition of 20 nm silica nanoparticles, at concentrations of 0.058, 0.24, and 0.4% wt., to the clean fluids generated the nano-fluids. Rheological data were gathered with Bohlin CS-50 rheometer within a temperature range of 75 to 175 °F. Silica nanoparticle concentrations of 0.058, 0.24, and 0.4% wt. were converted to 0.0083, 0.034, and 0.055 solid volume fractions respectively. Relative viscosity values could not be predicted using Einstein and Krieger-Dougherty equations. The nano-fluids display both increase and decrease in suspension viscosity; furthermore, their suspension viscosities were dependent on the solids volume fraction, temperature, and shear rate (9 to 1026 sec.). Lastly, relative viscosity correlations (that covered the whole range of values for which the experiments were conducted), previously developed by the authors, were included for complementary purpose. The correlations predict the viscosity of nano-suspensions as a function of solid volume fraction, temperature, and shear rate. This work provides an insight into the behavior of suspension at nano-scale level. The prediction of viscosity of nano-suspensions depends on more than one parameter. Moreover, this study will facilitate the field application of these novel hydraulic fracturing fluids.
Abstract Currently, there are few available publications regarding the application of nanotechnology in fluid loss control; hence, this technology needs more exploration. During hydraulic fracturing, fracture conductivity damage and other problems associated with excessive leak-off rate can be significantly curtailed by utilizing nano-fluid systems that evolve from further research studies. An experimental study is presented on the application of nanotechnology on filtration properties of surfactant-based fluids (SBF), polymeric fluids, and SBF-polymeric fluid blends. The concentration of SBF is 5%, while that of polymeric fluids is 33 lb/Mgal guar. Besides, both fluids contained 4% potassium chloride (KCl). Additionally, Blend-A and Blend-B were prepared by mixing SBF and polymeric fluids in the ratio of 75/25% vol. and 25/75% vol. respectively. Nano-fluids were prepared by adding 20 nm silica nanoparticles, at concentrations of 0.058, 0.24, and 0.4% wt., to the clean fluids. Filtration tests were conducted with a wall mount filter press, and at ambient temperature and 100 psi differential pressure. Excellent results were displayed with surfactant-based nano-fluids and Blend-A nano-fluids, but their outcome at 0.24 and 0.4% wt. respectively is slightly better. Polymeric nano-fluids and Blend-B nano-fluids revealed very good results, with better outcome at 0.24 and 0.058% wt. respectively. A trial run was made with a commercially available fluid loss additive (polyanionic cellulose, PAC) in polymeric fluids at the same nanoparticle concentrations; the result confirmed that nanosilica facilitates the achievement of a superior filtration property. Furthermore, Blend-A nano-fluid, at 0.058% wt., is selected as the best based on performance evaluation and economic analysis. In conclusion, the selected Blend-A nano-fluid at 0.058% wt. was optimized at lower nanoparticle concentrations (0.02, 0.01 and 0.002% wt.) in order to probe further into its filtration performance. Interestingly, using Blend-A nano-fluid at 0.002% wt., as regards the initial recommendation of 0.058% wt., reduces the cost of nanoparticles required for preparing 1 barrel of this fluid by 96.6%. Therefore, Blend-A nano-fluid is recommended for use at nanoparticles concentration of 0.002% wt. The application of Blend-A nano-fluid will promote fluid economy, substantially reduce fluid loss and fracture conductivity damage, and enhance production from unconventional reservoirs.
- Europe (0.93)
- North America > United States > Texas (0.28)
- Research Report > New Finding (0.34)
- Research Report > Experimental Study (0.34)
Comparison of Zirconia Nanoparticles with Conventionally Used Silica Nanoparticles for HTHP Drilling Applications
Ahmad, Hafiz Mudaser (Department of Chemical Engineering, University of Engineering & Technology Lahore, 54890 Pakistan) | Iqbal, Tanveer (Department of Chemical, Polymer & Composite Materials Engineering, University of Engineering & Technology, New Campus, Lahore, 54890 Pakistan) | Yaseen, Saima (Department of Chemical Engineering, University of Engineering & Technology Lahore, 54890 Pakistan) | AlNabbat, Yousif Yagoob (Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia) | Murtaza, Mobeen (Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia) | Mahmoud, Mohamed (Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia) | Patil, Shirish (Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia) | Kamal, Muhammad Shahzad (Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia)
Abstract Well-designed formulations of drilling fluids are required for drilling operations to improve rheological and filtration properties. The rheological properties and fluid loss during the drilling process are severely affected at the deep well with high temperature and pressure conditions. This study investigates the comparison of zirconia nanoparticles and conventionally used silica nanoparticles on rheological and filtration properties at temperatures ranging from 76°F to 122°F. Sodium-bentonite dispersion in deionized water was used as the base drilling fluid. Rheological properties were determined at different temperatures using a Discovery Hybrid rheometer with various concentrations of nanoparticles from 0.2 wt.% to 0.75 wt.% concentrations. Steady shear rheology experiments were performed to study drilling formulations’ shear stress, viscosity, and yield stress. Temperature ramp rheology tests at 76°F and 122°F were performed to analyze the effect of increasing temperature on viscosity. The filtration tests were conducted to study the fluid loss properties of drilling fluids at various concentrations of nanoparticles. Linear swelling analysis of clay in the presence of drilling muds was performed to study the shale inhibition properties of prepared drilling formulations. The incorporation of nanoparticles significantly enhanced the rheological properties such as yield stress and viscosity at various concentrations and temperatures. Rheological properties of zirconia muds compared with silica muds for various concentrations of nanoparticles. Temperature ramp rheology tests showed that zirconia muds have enhanced viscosity at 0.75 wt.% compared to the counterpart of silica mud. A decrease in fluid loss was observed for zirconia muds compared to the base mud while fluid loss increases with increasing concentration of silica nanoparticles. The incorporation of nanoparticles in the drilling fluids significantly reduced the swelling of clay compared to the swelling of clay in deionized water. This research supports the extensive interpretation of water-based drilling fluids using zirconia nanoparticles and a comparison of drilling properties with silica-based fluids for high-temperature applications. The potential use of zirconia nanoparticles in drilling fluid formulations provides the way forward for the improvement of fluid loss characteristics, shale inhibition, and rheological properties.
- Geology > Mineral (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.48)