Recent advances in chitin and chitosan/graphene-based bio-nanocomposites for energetic applications

Herein, we report recent developments in order to explore chitin and chitosan derivatives for energy-related applications. This review summarizes an introduction to common polysaccharides such as cellulose, chitin or chitosan, and their connection with carbon nanomaterials (CNMs), such as bio-nanocomposites. Furthermore, we present their structural analysis followed by the fabrication of graphene-based nanocomposites. In addition, we demonstrate the role of these chitin-and chitosan-derived nanocomposites for energetic applications, including biosensors, batteries, fuel cells, supercapacitors and solar cell systems. Finally, current limitations and future application perspectives are entailed as well. This study establishes the impact of chitin-and chitosan-generated nanomaterials for potential, unexplored industrial applications

Assessing the suitability of affordable housing based on demand criteria

Affordable housing has become essential to provide housing with affordable prices, but most of the locations of affordable housing are often not suitable with the people's demand. To assess the suitability of affordable housing, several initiatives has been developed, to match the demand and location of the affordable housing, but most the models lacks of spatial element, other model focusing on the goal related to site suitability to cities, and people's preferences of housing. This study aims to integrating spatial information and analysis to assessing the suitability level of affordable housing in Malaysia. This assessment model consists of 3 main indicators; suitability house according to neighbourhood context, demographic factor and commute distance. The method use in this study is using multi-Criteria Analysis, using weighted scoring techniques. The results show that most of the affordable housing score more than 60% average, with the highest score are 84% and the lowest score are 57.9%. this shows that the suitability level of affordable housing in the study area is good. These indicators can be used for further investigation of other affordable housing, and also in finding the suitable site for affordable housing in the future

The chemistry insight: epoxy sealant as an alternative remedial operation for well integrity

Epoxy resin is commonly used in the oil and gas industry due to its excellent toughness, low shrinkage, good adhesive strength, and relatively good thermal resistance. It is used for water shutoff, zonal isolation, cementing, enhanced oil recovery, and preventing leakage in wells. This paper reviews the chemistry aspect of using an epoxy resin system as a sealant to prevent well leakage and it offers insights into the chemistry of the epoxy resin system, as applied in previous studies. The paper also unveils the reasons for the application of this system from the chemistry perspective, allowing this aspect to be better understood. Success in the investigated cases depended on the formulation design. The epoxide and hydroxyl func�tional groups have been found to contribute substantially to the excellent performance of the sealant system. Furthermore, the amine curing agent triggers the abrupt reaction of the oxirane ring to stabilise when the cured sealant is perfectly applied. Based on the findings, it is suggested that other types of epoxies, namely epoxidised oils, require further study. Finally, in terms of safety an

Computer-assisted in coiled tubing perforation limitations: A case study from MA-X gas well

This paper seeks to determine the optimum operating conditions for deploying casing perforation guns based on CT to target depths in gas well MA-X by utilising Orpheus Model in CERBERUS. Orpheus assisted to solve the complicated scenarios and complex analysis involves mathematical modelling which is necessitates for computer processing powers. This study investigated four different Coiled Tubing (CT) intervention operational variables namely borehole assembly, CT grade outer diameter (OD), well fluid type and fractional reducer application included examined two scenarios which are running tools in (RIH) and pulling out from borehole (POOH). Only CT workstring with outer diameter between 1-1/4 inch and 2-7/8 inch is considered due to the wellbore completion minimum restriction. Constrained by economic and logistical reasons, only fresh water, 2% KCl, 15% HCl, sea water and diesel will be considered for the well bore fluid. Fractional reducer effects was simulated and analysed. Based on simulation results, the CT outer diameter 1-3/4 inch workstring optimized operation, the CT grade is QT1000 increased mechanical properties. A suitable well fluid is sea water with application of friction reducer improve CT perforation performances to achieve maximum target depth

Assessing safety level of affordable housing based on safe city concepts

Safety of residential areas, especially affordable housing has become an important aspect, and has been listed as part of Sustainable Development Goal (SDG) initiatives by the United Nation (UN). Several initiatives on measuring the safety level have been proposed, including Safe City Index 2019, Safe City Program, Defensible Space Concept, crime prevention through environmental design (CPTED), Smart Sustainable Cities, etc. However, some of these initiatives focus only on crime, others focus on steps to improve safety and other models that are broader but not specific to safety. Besides that, these models place less emphasis on the aspects of spatial assessment, especially the safety level assessment based on affordable housing location in Malaysia. To handle these issues, this study's aim is to enhance current indicators to assess the safety level of affordable housing, using Kuala Lumpur, Malaysia as a case study area. This study identified 6 indicators; crime, safety and security, infrastructure security, accessibility, natural disaster, and health security. Spatial analysis was done based on the indicators, and from the results, it shows that almost all of the affordable housing score are more than 50%, with the highest score is 76.50%, and the lowest score is 44.7%. This indicator can be used as a basis to assess the safety level of affordable housing, especially in Kuala Lumpur, Malaysia

Ultrasound-assisted nanofluid flooding to enhance heavy oil recovery in a simulated porous media

Herein thermally treated empty fruit bunch SiO2 nanoparticles (EFBSNP) was produced by ultrasound-assisted wet-milling and their effectiveness in enhancing cavitation effect of ultrasound to improve heavy oil recovery was evaluated. Empty fruit bunch ash (EFBA) was thermally treated to enhance its SiO2 content. Surface properties and size distribution of EFBSNP were studied using transmission electron microscopy and dynamic light scattering. X-ray diffractometer identified the crystal phase, the active group was ascertain using Fourier-transform infrared spectroscopy and thermal stability was established by differential scanning calorimetry. Moreover, the surface chemical composition was determined by X-ray photoelectron spectroscopy. The ability of empty fruit bunch SiO2 nanofluid (EFBSNF) to absorb ultrasound in heavy oil and the impact of ultrasound assisted EFBSNF flooding to enhance oil recovery of heavy oil was assessed. The microstructure analysis revealed EFBSNP of size ranges 17.78–115.38 nm with a purity of 94%. EFBSNF assisted ultrasound decreased interfacial tension to 0.2 mN/m, thus mobilizing the trapped oil droplet in the pores effectively. Ultrasound assisted EFBSNF flooding increased oil recovery by 44.33% compared to 26.33% without ultrasound

Dynamic modelling of reservoir fines retention by mesoporous silica nanofluid to improve oil recovery during low salinity water flooding of a consolidated sandstone

Mesoporous silica (SiO2) nanoparticles (MSNP) was used to stabilize formation fines for increased oil recovery during low salinity water flooding. Likewise, the effect of porous media length on dynamic retention of fines at high temperature reservoir condition was investigated. Breakthrough curves of reservoir fines adsorption by mesoporous SiO2 nanofluid (MSNF) were described using Thomas and Yoon-Nelson models. Similarly, effect of concentration, flow rate, porous media length and temperature on the retention capacity of reservoir fines was modelled using Box Behnken design of experiments. Subsequently, effect of reservoir fines stabilization on oil recovery was evaluated. Formation damage remediation propensity of MSNF was investigated. Finally, the oil recovery mechanisms were determined using the sessile drop contact angle and Wilhelmy plate methods. Experimental results of the dynamic adsorption with coefficient of determination (R2) values between 0.967 and 0.999 signifies that the reservoir fines adsorption by MSNF were well predicted by Thomas and Yoon-Nelson models. Consequently, MSNF stabilized the reservoir fines by attaching onto their surface rather than on the porous media thereby changing the wettability to water-wet, decreasing the contact angle to 16.1°, 17.1° and 20.7° for kaolinite, illite and montmorillonite, respectively. Thus, increasing oil recovery by 22–23% original oil in place

Structural analysis of Northwest Sabah basin by 2d reconstruction of seismic sections

The tectonic evolution of thrust fold belt and thrust sheet zone in Northwest Sabah basin was described based on balanced reconstruction of seismic sections representing Mid-Miocene to Recent deposits. The study area is located at the center of a wide crustal deformational zone bordered by the Sunda Shelf on the northeast, Sulu Sea in the southwest and the South China Sea in the northwest. Balancing cross section can be applied after the deformed geological structure geometry is accurately determined from seismic sections and 7 seismic stratigraphic unit from 15 Ma until Recent is consecutively restored. There are four steps involved in retro-deformation processes beginning with removing all faults displacements followed by unfolding the folds, isostasy correction and finally the removal of each compacted layer parts or decomposition. Wider fold wavelengths with least thrust faults were observed from south to north in the seismic sections ranging from 12 to 4 km with an average of about 7 km, while smaller fold wavelengths and more thrust faults were observed in the north based on the same seismic sections. In general, the reconstructed cross sections revealed compressional tectonic deformation activity as shown by shortening strain trending NW-SE. Measurement of total shortening shows that thrust fold belt is imbalance by an exceeds of 14.7 km and more active compared to thrust sheet zone which has only 0.9 km. Results of the study also indicate facies destruction due to shortening which is decreasing towards Pliocene or younger deposits

Seismic facies analysis and structural interpretation of deepwater NW Sabah

The deepwaters of NW Sabah has been an interesting site for deepwater hydrocarbon exploration in Malaysia. Up to now, the exploration in this is mainly focused to the Late Miocene until the Pliocene siliciclastic sediment reservoirs distribution at the shelf edge. This paper shows a gross seismic facies mapping analysis and structural interpretation of regional deepwater NW Sabah especially at Sabah Trough. To convert depth, all seismic lines were picked and tied with selected wells. The results of the interpretation were then summarized and presented with relation to regional tectonic events. Eight seismic stratigraphic units, six seismic facies together with five sequence boundaries were recognized. Multichannel reflection 2D seismic data, gamma ray logs and biostratigraphy description from the three wells at deepwater fold-thrust belt and published tectonostratigraphic scheme from Dangerous Grounds (Sabah Platform) in South China Sea were selected in this study. The propose of this study is to document the relevance of regional tectonic event between Dangerous Ground and Sabah Trough

Foam stability and electrokinetic phenomena: Comparison between simulation and experimental results

This work evaluated foam stability and electrokinetic phenomena that occurs in a sand pack simulation model when undergoing a foam injection process. The method used was a Finite Element Method. To evaluate a wide range of possible foam conditions, Sodium Dodecyl Sulphate with three different surfactant concentration (7500, 10 000 and 12 500 ppm) was used, obtaining a range of output voltage of 0.42-0.74 mV. One of surfactant characteristic in this study is biosurfactant which is environmental friendly and were used in previous experimental and simulation work. The numerical simulation were performed using 2 Dimensional rectangle geometry setup with a 30.4 cm length and 3.4 cm diameter which acts as a sand pack model and applying multiphysics (computational fluid dynamics, chemical reaction engineering, microelectromechanicals, electrochemistry and electrodeposition module) to simulate the numerical model. The simulation results obtained from the model implemented in COMSOL were used to compare with previous experimental and simulation work in relation to foam stability and associated streaming signals. Based on the comparison, the electrokinetic signal measurement was found to decrease with increasing surfactant concentration. However, the output voltage was slightly different due to different type of model used, different electrode geometry and arrangement, and some uncertainties caused by human error which affect the accuracy and sensitivity of the measurement. Therefore, monitoring foam progression in enhanced oil recovery is necessary to ensure the effectiveness of foam injection process