An Experimental Study on the Applicability of Water-alternating-CO2 Injection in the Secondary and Tertiary Recovery in One Iranian Reservoir

Abstract

The objective of this study was to experimentally investigate the performance of water-alternating gas (WAG) injection in one of Iran's oil reservoirs that encountered a severe pressure drop in recent years. Because one of the most appropriate studies to evaluate the reservoir occurs generally on rock cores taken from the reservoir, core samples drilled out of the reservoir's rock matrix were used for alternating injection of water and gas. In the experiments, the fluid system consisted of reservoir dead oil, live oil, CO₂, and synthetic brine; the porous media were a number of carbonate cores chosen from the oilfield from which the oil samples had been taken. All coreflood experiments were conducted using live (recombined) oil at 1,700 psi and reservoir temperature of 115°F. A total of four displacement experiments were performed in the core, including two experiments on secondary WAG injection and others on the tertiary water and gas invaded zones WAG injections. Prior to each test porosity and permeability of dried cores were calculated then 100% water-saturated cores were oil-flooded to obtain connate water saturation. Therefore, all coreflooding tests started with the samples at irreducible water saturation. Parameters such as oil recovery factor, water cut, and gas-oil ratio and production pressure of the core were recorded for each test. The most similar experimental work with the main reservoir condition, indicated that approximately 64% oil were recovered after 1 pore volume of WAG process at 136,000 ppm brine salinity. Although tests show ultimate recovery of 79% and 55% for secondary and tertiary injection in gas and water invaded zones, respectively, immiscible WAG injection efficiency in the gas and water invaded zones will not be proper. In the similar test to field properties, the average pressure difference about 70 Psig was observed, which shows stable front displacement. These experiments showed that there was significant improvement in the oil recovery for alternating injection of water and CO₂, especially in the secondary recovery process. Water breakthrough time in almost all of the tests shows frontal displacement of injected fluid in cores and produced gas-oil ratio changes a little whenever the injection is miscible and increases rapidly in immiscible processes.     

Minimizing makespan in a group shop with fuzzy release dates and processing times

This paper deals with a fuzzy group shop scheduling problem. The group shop scheduling problem is a general formulation that includes the flow shop, the job shop, and the open shop scheduling problems. Job release dates and processing times are considered to be triangular fuzzy numbers. The objective is to find a job schedule that minimizes the maximum completion time or makespan. First, the problem is formulated in a form of fuzzy programming and then prepared in a form of deterministic mixed binary integer linear programming by applying the chance-constrained programming. To solve the problem, an efficient genetic algorithm hybridized with an improvement procedure is developed. Both Lamarckian and Baldwinian versions are then implemented and evaluated through computational experiments.     

Application of a Novel,Heated, Nine-Reflection ATR Crystal and a Portable FTIR Spectrometer to the Rapid Determination of Total <Emphasis Type="Italic">Trans</Emphasis> Fat

Since trans fat labeling requirements became mandatory in the US and many other countries, there has been a need for rapid and accurate analytical methodologies that can facilitate compliance with the various regulations. The determination of total trans fatty acids by mid-infrared (IR) spectroscopy is a widely used procedure that was standardized and validated as AOCS Official Method Cd 14e-09 (negative second derivative infrared spectroscopic method for the rapid (5 min) determination of total isolated trans fat) in 2009. The C–H out-of-plane deformation mid-IR band observed at 966 cm⁻¹ is uniquely characteristic of isolated (non-conjugated) double bonds with trans configuration. AOCS Official Method Cd 14e-09, the most recent attenuated total reflection-Fourier transform IR (ATR-FTIR) official method, entails the measurement of the height of the negative second derivative of the trans absorption band. In the present study, the performance of a novel, portable FTIR system equipped with a heated 9-bounce diamond ATR crystal was evaluated and compared to that of a conventional benchtop single-bounce ATR-FTIR spectrometer. The introduction of the 9-bounce diamond ATR crystal resulted in the lowering of the limit of quantification of trans fat, as a percentage of the total fat, from approximately 2 to 0.34%. The data collected from accurately weighed gravimetric standards and 28 unknown test samples ranging in trans fat content from about 0.5 to 54%, as a percentage of the total fat, indicated that this IR official method and the use of the new 9-bounce portable ATR-FTIR instrumentation could lead to a five-fold enhancement in sensitivity relative to single-bounce systems. Implementing these changes would facilitate regulatory compliance and verification of fat and oil samples for trans fat content in the US and other countries, since all of the published regulations (e.g., “0 g trans fat per serving”) have levels of trans fat, as percentage of total fat, that exceed 0.34%.     

Application of chance-constrained programming for stochastic group shop scheduling problem

In this paper, we study a group shop scheduling (GSS) problem subject to uncertain release dates and processing times. The GSS problem is a general formulation including the other shop scheduling problems such as the flow shop, the job shop, and the open shop scheduling problems. The objective is to find a job schedule which minimizes the total weighted completion time. We solve this problem based on the chance-constrained programming. First, the problem is formulated in a form of stochastic programming and then prepared in a form of deterministic mixed binary integer linear programming such that it can be solved by a linear programming solver. To solve the problem efficiently, we develop an efficient hybrid method. Exploiting a heuristic algorithm in order to satisfy the constraints, an ant colony optimization algorithm is applied to construct high-quality solutions to the problem. The proposed approach is tested on instances where the random variables are normally, uniformly, or exponentially distributed.     

TiO2 nanoparticles catalysed synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles using hydrogen peroxide under ambient light

A H₂O₂/TiO₂ P25 nanoparticle system has been examined and applied towards synthesis of a wide range of 2-substituted benzimidazole and benzothiazole derivatives from oxidative coupling of aromatic 1,2-phenylendiamine and 2-aminothiophenol with aromatic aldehydes bearing different types of substituents.     

Improving hyperspectral image classification by combining spectral,texture, and shape features

Several studies have already demonstrated the efficiency of utilizing spatial information in representation and interpretation of hyperspectral (HS) images. Texture and shape features are known as two important categories of spatial information in various applications of image processing. This study tries to utilize texture and shape features extracted from HS images, as well as spectral information, in order to reduce overall classification errors. These features include morphological profiles (MPs), global Gabor features, and features extracted from conventional and segmentation-based grey-level co-occurrence matrices (GLCMs). Various combinations of these spatial features along with spectral information are fed into a support vector machine (SVM) classifier, and the best combinations for different situations are determined. Experiments on the widely used Indian Pines, Pavia University, and Salinas HS data sets demonstrate the efficiency of the proposed framework in comparison with some recent spectral–spatial classification methods.     

Moment-based feature extraction from high spatial resolution hyperspectral images

In this article, we propose a method for extracting spatio-spectral features from high spatial resolution hyperspectral (HS) images. The method is based on extracting two-dimensional moments from neighbourhoods of pixels. Three different types of moments are considered: geometric, complex Zernike and Legendre. Moments of a given type are extracted from a few principal components (PC) of HS data, and are stacked on the original HS data to form a joint spatio-spectral feature space. These features are classified using a support vector machine (SVM) classifier. The influence of the moments orders and the size of the neighbourhood window on the quality of the extracted features are analysed. A few experiments are conducted on two widely used HS data sets, Pavia University and Salinas. The results demonstrate high capabilities of the proposed method in comparison with some state-of-the-art spatio-spectral HS classification methods.     

Techniques,perspectives, and challenges of bioactive peptide generation: A comprehensive systematic review

Due to the digestible refractory and absorbable structures of bioactive peptides (BPs), they could induce notable biological impacts on the living organism. In this regard, the current study was devoted to providing an overview regarding the available methods for BPs generation by the aid of a systematic review conducted on the published articles up to April 2019. In this context, the PubMed and Scopus databases were screened to retrieve the related publications. According to the results, although the characterization of BPs mainly has been performed using enzymatic and microbial in‐vitro methods, they cannot be considered as suitable techniques for further stimulation of digestion in the gastrointestinal tract. Therefore, new approaches for both in‐vivo and in‐silico methods for BPs identification should be developed to overcome the obstacles that belonged to the current methods. The purpose of this review was to compile the recent analytical methods applied for studying various aspects of food‐derived biopeptides, and emphasizing generation at in vitro, in vivo, and in silico.