Novel Coupling Smart Water-CO₂ Flooding for Sandstone Reservoirs; Smart Seawater-Alternating-CO₂ Flooding (SMSW-AGF)

CO2 flooding is an environmentally friendly and cost-effective EOR technique that can be used to unlock residual oil from oil reservoirs. Smart water is any water that is engineered by manipulating the ionic composition, regardless of the resulting salinity of the water. One CO2 flooding mechanism is wettability alteration, which meets with the main smart water flooding function. Injecting CO2 alone raise an early breakthrough and gravity override problems, which have already been solved using water alternating gas (WAG) using regular water. WAG is an emerging enhanced oil recovery process designed to enhance sweep efficiency during gas flooding. In this study, we propose a new method to improve oil recovery via synergistically smart seawater with CO2. This new method takes advantage of the relative strengths of both processes. We hypothesized that SW depleted in NaCl provided more oil recovery. We also added that depleting NaCl in seawater is not the end of the story; diluting divalent cations/anions in the seawater depleted in NaCl provides higher oil recovery. Injecting smart seawater depleted in NaCl with diluted Ca2+ and CO2 resulted in a high oil recovery percentage among the other scenarios. Thus, the above water design was applied as a WAG in three cycles, which resulted in a much higher oil recovery of 24.5% of the OOIP. This improved heavy oil recovery is a surprising and promising percentage. The spontaneous imbibition agreed with the oil recovery results. This study sheds light on how manipulating ions in the water used in WAG can significantly enhance oil recovery

Novel Coupling Smart Water-CO₂ Flooding for Sandstone Reservoirs

CO2 flooding is an environmentally friendly and cost-effective EOR technique that can be used to unlock residual oil from oil reservoirs. Smart water is any water that is engineered by manipulating the ionic composition, regardless of the resulting salinity of the water. One CO2 flooding mechanism is wettability alteration, which meets with the main smart water flooding function. Injecting CO2 alone increases the likelihood of an early breakthrough and gravity override problems, which have already been solved using water-alternating-gas (WAG) using regular water. WAG is an emerging enhanced oil recovery process designed to enhance sweep efficiency during gas flooding. In this study, we propose a new method to improve oil recovery via synergistically smart brine with CO2. This new method takes advantage of the relative strengths of both processes. We hypothesized that brine depleted in NaCl provides more oil recovery. We also determined that depleting NaCl in brine is not the end of the story; diluting divalent cations/anions in the brine depleted in NaCl provides higher oil recovery. Injecting smart brine depleted in NaCl with diluted Ca2+ and CO2 resulted in a high oil recovery percentage among the other scenarios. Thus, the above water design was applied as a WAG in three cycles, which resulted in a much higher oil recovery of 24.5% of the OOIP. This improved heavy-oil recovery is a surprising and promising result. The spontaneous imbibition agreed with the oil-recovery results. This study sheds light on how manipulating ions in the water used in WAG can significantly enhance oil recovery

Comparison between Cold/Hot Smart Water Flooding in Sandstone Reservoirs

The incremental oil recovery has been investigated and approved by many laboratory and field projects using water flooding in tertiary stage. The salinity of the injected water is an important factor observed by many researchers. The more salinity decreases the more oil recovery obtained. The investigations on the hot low salinity water flooding have been conducted by many researchers and they found out that it is useful for increasing oil recovery especially heavy oil due to reducing oil viscosity and make it easy to produce to the surface. The thermal expansion of water plays an important role in the incremental oil recovery mechanism, reducing the density of the injected water relative to the aquifer water. This reduces mixing; minimizing thermal loses to the aquifer. Hot water flooding may also increase the economic life of individual wells by as much as a factor of two. Smart water was also used to alter the reservoir wettability and increase oil recovery by manipulating the divalent cations in the injected water. In this study, we used hot and cold smart water and injected both into the sandstone saturated with crude oil in order to investigate the important role of smart water itself and hot smart water. The systematic results showed that changing some cations in the injected brines was better than to spend more money to heat the smart water. The divalent cations Ca2+ and Mg2+ were the most effective component in the smart water. In this study, we also studied the pH effect of the cold/hot smart water effluent smart water EOR

Selective Laser Melting of Ni-Rich NiTi: Selection of Process Parameters and the Superelastic Response

Material and mechanical properties of NiTi shape memory alloys strongly depend on the fabrication process parameters and the resulting microstructure. In selective laser melting, the combination of parameters such as laser power, scanning speed, and hatch spacing determine the microstructural defects, grain size and texture. Therefore, processing parameters can be adjusted to tailor the microstructure and mechanical response of the alloy. In this work, NiTi samples were fabricated using Ni50.8Ti (at.%) powder via SLM PXM by Phenix/3D Systems and the effects of processing parameters were systematically studied. The relationship between the processing parameters and superelastic properties were investigated thoroughly. It will be shown that energy density is not the only parameter that governs the material response. It will be shown that hatch spacing is the dominant factor to tailor the superelastic response. It will be revealed that with the selection of right process parameters, perfect superelasticity with recoverable strains of up to 5.6% can be observed in the as-fabricated condition

A Novel Technique For The Quantitative Determination Of Wettability Of A Severely Heterogeneous Tight Carbonate Reservoir

The objective of this study is to accurately measure the wettability contact angle of a cretaceous carbonate reservoir in a vertical well set-up known for as an unconventional tight carbonate oil reservoir. Also, to investigate the relative heterogeneity of these samples using digitally captured images; these images accurately capture natural pore-system in this carbonate rock samples and their wettability performance attributed towards building a vertical depth wettability/heterogeneity model. To capture, measure and model natural tight matrix static contact angle wettability in order to understand their new physics that will advance unconventional tight oil reservoir characterization. Entire vertical well depth reservoir core rock samples, in the form of rock fragments, are selected, then imaged, and then characterized for porosity, permeability, tortuosity/heterogeneity, and pore/grain-wettability contact angle in 2D format utilizing SEM-BSE imaging techniques. The generated big data images will be quantified using pre-defined logic for tortuosity/heterogeneity and wettability contact angle measurement. Each rock sample will process several images captured at X40 (mm), X400 (μm), and X4000 (nm) magnifications and will investigate wettability/heterogeneity relationships for unconventional tight pore system from the entire vertical depth. From measured data and computed logics, the major portions of captured rock investigated show water wet tendency. The wettability distribution in the vertical 250 feet shows strong to medium and even weak water-wet system variation (θ = 10° - θ = 90°). The dominant wettability is medium-water-wet (θ = 30° - θ = 60°), and it is found in the middle section of the vertical column. Medium-water-wet indicates a good candidate for secondary recovery water injection development programs. This study includes tortuosity/heterogeneity quantifications from imaging 2D technology which is valuable in understanding vertical/horizontal fluid movements. The authors feel that this study will narrow the gap in understanding contact angle wettability, heterogeneity characterizations from static conditions viewpoint and hence, the reservoir crude oil recovery vertical profile history from vertical rock samples

Influence of SLM on Compressive Response of NiTi Scaffolds

Porous Nickel-Titanium shape memory alloys (NiTi-SMAs) have attracted much attention in biomedical applications due to their high range of pure elastic deformability (i.e., superelasticity) as well as their bone-level modulus of elasticity (E≈12-20 GPa). In recent years, Selective Laser Melting (SLM) has been used to produce complex NiTi components. The focus of this study is to investigate the superelasticity and compressive properties of SLM NiTi-SMAs. To this aim, several NiTi components with different level of porosities (32- 58%) were fabricated from Ni50.8Ti (at. %) powder via SLM PXM by Phenix/3D Systems, using optimum processing parameter (Laser power-P=250 W, scanning speed-v=1250mm/s, hatch spacing-h=120μm, layer thickness-t=30μm). To tailor the superelasticity behavior at body temperature, the samples were solution annealed and aged for 15 min at 350°C. Then, transformation temperatures (TTs), superelastic response, and cyclic behavior of NiTi samples were studied. As the porosity was increased, the irrecoverable strain was observed to be higher in the samples. At the first superelastic cycle, 3.5%, 3.5%, and 2.7% strain recovery were observed for the porosity levels of 32%, 45%, and 58%, respectively. However, after 10 cycles, the superelastic response of the samples was stabilized and full strain recovery was observed. Finally, the modulus of elasticity of dense SLM NiTi was decreased from 47 GPa to 9 GPa in the first cycle by adding 58% porosity

Practical Imaging Applications Of Wettability Contact Angles On Kuwaiti Tight Carbonate Reservoir With Different Rock Types

This study focuses on a tight carbonate reservoir which is located in Northern Kuwait and is classified as an unconventional reservoir. A practical imaging technique of wettability contact angle (θ°) presents big data as well as relative-permeability (Krw and Kro) measurements. Also, modeling, through rock image technology, the vast well-documented grain/pore boundary morphology available inside fresh rock fragments have achieved good results. Conventional laboratory relative-permeability experiments are expensive and time-consuming. This study introduces a novel method to measure/calculate relative permeability through fast, less expensive, non-destructive, and environmentally friendly techniques of imaging technology. One tight carbonate reservoir is selected, imaged, processed, analyzed, and then modeled using several pore diameter morphological models. The images are captured using a backscattered electron microscopy BSE-SEM technology analyses. In this study, two-dimensional images are used to characterize the morphology of selected samples grains and pores, using a two-step technique. In the first step, the image is captured using a backscattered electron detector (BSE), digital electron microscopy imaging, and pore-counting processing technology. All of the sample grain/pore features captured in the image are reported in micrometer units. In the second step, the pore area of such features is scanned using image analysis software that can accurately measure several morphological parameters of pore and grain spaces. A robust technique of visual estimate is used, which has the advantage of speeding the image analysis process. The visual analysis software tool counts different pores and counts grains and also measures their shapes and sizes which are crucial for relative permeability calculations. Several pore morphological models have been considered for optimum accuracy comparisons, including pore/grain relationships (area/perimeter), pore contact angle (θ), and pore count. Relative permeability is calculated based on the area of the pore/grain features measured from two-dimensional images. The study objectives are to accurately measure the wettability contact angle of huge pore geometries using 2D image technology to understand the nature of the pore network in the candidate reservoir. To study the relative permeability of internal influences of pore and grain morphology needed for enhanced oil recovery/improved oil recovery (EOR/IOR) future programs. And, finally, to measure relative permeability faster and more accurately

Kuwaiti Carbonate Reservoir Oil Recovery Prediction Through Static Wettability Contact Angle Using Machine Learning Modeling

The objective of this study is to predict EOR efficiencies through static wettability contact angle measurement by Machine Learning (ML) modeling. Unlike conventional methods of measuring static wettability contact angle, the unconventional digital static wettability contact angle is captured and measured, then (ML) modeled in order to forecast the recovery based on wettability distribution phenomenon. Due to success in big data collection from reservoir imaging samples, this study applies data science lifecycle logic and utilizes Machine Learning (ML) models that can predict the recovery through wettability contact angles and thus identify the treatment of oil recovery for a candidate reservoir. Using developed morphological driven pixel-data and transformed numerical wettability contact angle data are acquired from Scanning Electron Microscope Backscattered Electron (SEM-BSE) for 27 fresh core samples from top to bottom of the reservoir. These samples are properly sequenced and then images are selected. Big data from imaging technology have been processed in a manner to train, and test the model accuracy. Applied Data Science Lifecycle technique, such as data mining, is utilized. Data Exploration Analysis (DEA) is implemented to understand and review data distribution as well as relationships among input features. Different supervised ML models to predict recovery are utilized and an optimal model is identified with an acceptable accuracy. The selected prediction model is applied to model the optimal recovery practice. Extreme Gradient Boosting (XGBoost) algorithm is utilized and found as a best-fit model for this Kuwaiti reservoir case practice. Moreover, decision tree and Artificial Neural Network (ANN) models could provide acceptable accuracy. Other supervised learning models were attempted and were not promising to provide feasible accuracy for this carbonate reservoir. The novel of this unique solution of the data-driven ML model is to predict recovery based on static wettability contact angles (?°). The static wettability contact angles (?°) and pore morphological features introduce an insights method to support reservoir engineers in making value-added decisions on production mechanisms and hydrocarbon recovery for their reservoirs. Hence, it improves the field development strategy

Achieving Superelasticity in Additively Manufactured NiTi in Compression Without Post-Process Heat Treatment

Shape memory alloys (SMAs), such as Nitinol (i.e., NiTi), are of great importance in biomedical and engineering applications due to their unique superelasticity and shape memory properties. In recent years, additive manufacturing (AM) processes have been used to produce complex NiTi components, which provide the ability to tailor microstructure and thus the critical properties of the alloys, such as the superelastic behavior and transformation temperatures (TTs), by selection of processing parameters. In biomedical applications, superelasticity in implants play a critical role since it gives the implants bone-like behavior. In this study, a methodology of improving superelasticity in Ni-rich NiTi components without the need for any kind of post-process heat treatments will be revealed. It will be shown that superelasticity with 5.62% strain recovery and 98% recovery ratio can be observed in Ni-rich NiTi after the sample is processed with 250 W laser power, 1250 mm/s scanning speed, and 80 µm hatch spacing without, any post-process heat treatments. This superelasticity in as-fabricated Ni-rich SLM NiTi was not previously possible in the absence of post-process heat treatments. The findings of this study promise the fast, reliable and inexpensive fabrication of complex shaped superelastic NiTi components for many envisioned applications such as patient-specific biomedical implants

An investigation into the roles of chlorides and sulphate salts on the performance of low salinity injection in sandstone reservoirs : experimental approach

Numerous studies have been carried out to ascertain the mechanisms of low salinity and smart water flooding technique for improved oil recovery. Focus were often on brine composition and, specifically the cationic content in sandstone reservoirs. Given the importance of the salt composition and concentration, tweaking the active ions which are responsible for the fluids-rock equilibrium will bring into effect numerous mechanisms of displacement which have been extensively debated. This experimental study, however, was carried out to evaluate the extent of the roles of chloride and sulphate-based brines in improved oil recovery. To carry this out, 70,000 ppm sulphates and chloride-based brines were prepared to simulate formation water and 5,000ppm brines of the same species as low salinity displacement fluids. Core flooding process was used to simulate the displacement of oil by using four (4) native sandstones core samples, obtained from Burgan oil field in Kuwait, at operating conditions of 1500 psig and 50oC. The core samples were injected with 70,000 ppm chloride and sulphates and subsequently flooded with the 5,000 ppm counterparts in a forced imbibition process. Separate evaluations of chloride and sulphate-based brines were carried out to investigate the displacement efficiencies of each brine species. The results showed that the in both high and low salinity displacement tests, the SO4 brine presented better recovery of up to 89% of the initial oil saturation (Soi). Several mechanisms of displacement were observed to be responsible for improved recovery during SO4 brine displacement. IFT measurement experiments also confirmed that there was reduction in IFT at test conditions between SO4 brine and oil and visual inspection of the effluent showed a degree emulsification of oil and brines. Changes in pH were observed in the low salinity flooding and negligible changes were noticed in the high salinity floods. These results provide an insight into the roles of chloride and sulphate ions in the design of smart “designer” water and low salinity injection scenarios