scholarly journals The phase inversion mechanism of the pH-sensitive reversible invert emulsion from w/o to o/w

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 380-390
Author(s):  
Fei Liu ◽  
Yanling Wang ◽  
Xiaqing Li ◽  
Zhaoxiang Zhang ◽  
Xiaodong Dai ◽  
...  

AbstractAlteration in the environmental conditions will cause a reversed reaction between o/w emulsion and w/o emulsion that has similar advantages of different liquids form on the reversible invert emulsion. The reversible phase inversion of the emulsion has a benefit of dealing with drilling cutting, so the reversible invert emulsion also can be thought used as a drilling fluid. The phase inversion from w/o emulsion to o/w emulsion can be divided into three stages. They are w/o emulsion, w/o/w emulsion, and o/w emulsion. In the w/o emulsion stage, the structure appeared among water droplets when the percentage of the HCl solution (5%) was less than 0.375%. In the w/o/w emulsion stage, the structure among water droplets existed at the beginning of this stage; however, the internal phase and the external phase can interchange their positions during the process. In the third stage, the structures among droplets of the emulsion would be broken and the degree of the dispersion of the oil droplet in the emulsion would increase. The changes in the microstructure, conductivity, electrical stability, standing stability, and the viscosity of the emulsion, which have edified among droplets in the process from w/o emulsion to o/w emulsion, were studied. The result of the microstructure microscopic observation agrees with the result of the electrical stability and viscosity experiments. Moreover, the internal phase and the external phase can interchange positions during the process.

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2393 ◽  
Author(s):  
Salaheldin Elkatatny

Drilling in high-pressure high-temperature (HPHT) conditions is a challenging task. The drilling fluid should be designed to provide high density and stable rheological properties. Barite is the most common weighting material used to adjust the required fluid density. Barite settling, or sag, is a common issue in drilling HPHT wells. Barite sagging may cause many problems such as density variations, well-control problems, stuck pipe, downhole drilling fluid losses, or induced wellbore instability. This study assesses the effect of using a new copolymer (based on styrene and acrylic monomers) on the rheological properties and the stability of an invert emulsion drilling fluid, which can be used to drill HPHT wells. The main goal is to prevent the barite sagging issue, which is common in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature >300 °F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400 °F, which indicates the prevention of barite settling at high temperature.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4532
Author(s):  
Sławomir Błaż ◽  
Grzegorz Zima ◽  
Bartłomiej Jasiński ◽  
Marcin Kremieniewski

One of the most important tasks when drilling a borehole is to select the appropriate type of drilling fluid and adjust its properties to the borehole’s conditions. This ensures the safe and effective exploitation of the borehole. Many types of drilling fluids are used to drill holes for crude oil and natural gas. Most often, mainly due to cost and environmental constraints, water-based muds are used. On the other hand, invert drilling fluids are used for drilling holes in difficult geological conditions. The ratio of the oil phase to the water phase in invert drilling fluids the most common ratio being from 70/30 to 90/10. One of the disadvantages of invert drilling fluids is their cost (due to the oil content) and environmental problems related to waste and the management of oily cuttings. This article presents tests of invert drilling fluids with Oil-Water Ratio (OWR) 50/50 to 20/80 which can be used for drilling HPHT wells. The invert drilling fluids properties were examined and their resistance to temperature and pressure was assessed. Their effect on the permeability of reservoir rocks was also determined. The developed invert drilling fluids are characterized by high electrical stability ES above 300 V, and stable rheological parameters and low filtration. Due to the reduced content of the oil, the developed drilling fluid system is more economical and has limited toxicity.


2014 ◽  
Vol 884-885 ◽  
pp. 186-189 ◽  
Author(s):  
San Zhu ◽  
Xiao Gang Luo ◽  
Li Bin Ma ◽  
Ya Nan Xue ◽  
Ning Cai ◽  
...  

Novel composite resins with dual absorption properties of water and oil are prepared by the polymerization of high internal phase emulsion (HIPEs) with n-butyl methacrylate as the external phase monomer and acrylamide as the internal phase monomer. The subsequent polymerization leads to the formation of water and oil dual-absorption composite resins. The morphology of porous structure and microcosmic phase separation after water/oil uptake is observed by scanning electron microscopy (SEM). The water and oil absorbency strongly depend on composition. The composites with saturated water uptake could absorb the chloroform again but cant absorb water if saturated with chloroform first. And the resins exhibit great reusability, keeping almost constant absorbency. The present methodology could be a potential approach to obtain amphiphilic composites, which possess potential applications in the bioengineering, medical and industrial fields.


Author(s):  
Jianzhong Yang ◽  
Joseph Szabo ◽  
Reza E. Osgouei ◽  
Joseph Arensdorf ◽  
Rosa Swartwout ◽  
...  

2021 ◽  
Author(s):  
Vikrant Wagle ◽  
Abdullah Yami ◽  
Michael Onoriode ◽  
Jacques Butcher ◽  
Nivika Gupta

Abstract The present paper describes the results of the formulation of an acid-soluble low ECD organoclay-free invert emulsion drilling fluid formulated with acid soluble manganese tetroxide and a specially designed bridging package. The paper also presents a short summary of field applications to date. The novel, non-damaging fluid has superior rheology resulting in lower ECD, excellent suspension properties for effective hole cleaning and barite-sag resistance while also reducing the risk of stuck pipe in high over balance applications. 95pcf high performance invert emulsion fluid (HPIEF) was formulated using an engineered bridging package comprising of acid-soluble bridging agents and an acid-soluble weighting agent viz. manganese tetroxide. The paper describes the filtration and rheological properties of the HPIEF after hot rolling at 300oF. Different tests such as contamination testing, sag-factor analysis, high temperature-high pressure rheology measurements and filter-cake breaking studies at 300oF were performed on the HPIEF. The 95pcf fluid was also subjected to particle plugging experiments to determine the invasion characteristics and the non-damaging nature of the fluids. The 95pcf HPIEF exhibited optimal filtration properties at high overbalance conditions. The low PV values and rheological profile support low ECDs while drilling. The static aging tests performed on the 95pcf HPIEF resulted in a sag factor of less than 0.53, qualifying the inherent stability for expected downhole conditions. The HPIEF demonstrated resilience to contamination testing with negligible change in properties. Filter-cake breaking experiments performed using a specially designed breaker fluid system gave high filter-cake breaking efficiency. Return permeability studies were performed with the HPIEF against synthetic core material, results of which confirmed the non-damaging design of the fluid. The paper thus demonstrates the superior performance of the HPIEF in achieving the desired lab and field performance.


2015 ◽  
Vol 75 (1) ◽  
Author(s):  
A. L. Ahmad ◽  
M. M. H. Shah Buddin ◽  
B. S. Ooi ◽  
Adhi Kusumastuti

The aim of this research is to quantify the occurrence of membrane breakage in vegetable oil based Emulsion Liquid Membrane (ELM). Basically, ELM consists of three main phases; internal, external and membrane. In this work, the membrane phase was prepared by dissolving Span 80 as surfactant and Aliquat 336 as carrier in commercial grade corn oil. As a way to promote sustainable development, vegetable oil which is environmentally benign diluent was incorporated in the formulation of ELM. The influence of several important parameters towards membrane breakage were studied. They are carrier and surfactant concentration, W/O volume ratio, emulsification time, internal phase concentration as well as stirring speed. Based on the data obtained, emulsion prepared using 4 wt% Aliquat 336 and 3 wt% Span 80 resulted in the most stable emulsion with only 0.05% membrane breakage. The emulsion was produced using W/O volume ratio of 1/3 and it was homogenized with the assistance of ultrasound for 15 min. Moreover, emulsion produced able to provide a fair balance between emulsion stability and Cd(II) permeability as it able to remove 98.20% Cd(II) ions from the external phase. 


2013 ◽  
Vol 30 ◽  
pp. 87-96 ◽  
Author(s):  
E. Santamaría ◽  
M. Cortés ◽  
A. Maestro ◽  
M. Porras ◽  
J. M. Gutiérrez ◽  
...  

High internal phase ratio emulsions (HIPRE) or highly concentrated emulsions are characterized by their large internal phase volume.The nature and concentration of surfactant affects several features of the final emulsion, such as stability, droplet size and structure of the external phase. Therefore, an ordered external mesophase (structure of liquid crystal) can be obtained. The present work studies the influence of composition and preparation variables on the final properties of HIPRE with an external phase formed by a bicontinuous cubic liquid crystal. The studied outputs variables were droplet size, stability and rheological parameters as yield stress, viscosity at a fixed shear rate and the plateau value of the storage modulus. O/W HIPREs were prepared with a decane/brij 35/water system. Once the emulsions were characterized the meso/macroporous material was obtained. In order to prepare the materials, the emulsions were formed by incorporating the catalyst of the reaction (HCl) in the continuous phase. When the emulsions were formed, tetraethylorthosilicate (TEOS) was added as a silica source In order to optimize the production process a study of reutilization and recovery of some of the raw materials (i.e: the surfactant and the EtOH used) was done.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9374Journal of Nepal Chemical Society Vol. 30, 2012 Page:  87-96 Uploaded date: 12/19/2013   


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