A New Method of Evaluating the Filter-Cake Removal Efficiency

2002 ◽  
Author(s):  
C.R. Miranda ◽  
J.C. Leite ◽  
R.T. Lopes ◽  
L.F. Oliveira
Keyword(s):  
Removal Efficiency ◽  
Filter Cake ◽  
New Method ◽  
Cake Removal

scholarly journals One-Stage Calcium Carbonate Oil-Based Filter Cake Removal Using a New Biodegradable Acid System

2019 ◽  
Vol 11 (20) ◽  
pp. 5715 ◽  
Author(s):  
Salaheldin Elkatatny
Keyword(s):  
Calcium Carbonate ◽  
Removal Efficiency ◽  
Filter Cake ◽  
Acid System ◽  
Berea Sandstone ◽  
Core Samples ◽  
One Stage ◽  
Removal Experiments ◽  
Indiana Limestone ◽  
Cake Removal

Removal of the oil-based filter cake is a complex task especially in horizontal and multilateral wells. The presence of oil makes the removal process more challenging because the oil coats the weighting materials and prevents acid–filter cake interaction. Therefore, different additives are required to change the wettability of the filter cake to enhance the removal efficiency. This paper introduces a new biodegradable acid system (NBAS) that can efficiently remove oil-based filter cake in horizontal and multilateral wells where calcium carbonate is used as a weighting agent. The new biodegradable acid system (NBAS) consists of 50 vol.% biodegradable acid and 5 vol.% mutual solvent, and the remaining percent is deionized water. High-pressure high-temperature (HPHT) filtration experiments were performed to evaluate the filter cake removal efficiency and the retained permeability. The filtration and removal experiments were conducted using real core samples (Indiana limestone and Berea sandstone) at a temperature of 212 °F and 300 psi differential pressure. Afterward, the NBAS was evaluated by measuring physical properties and conducting corrosion, compatibility, and thermal stability studies. The obtained results showed that the NBAS was compatible and thermally stable for more than 48 h at 212 °F and 300 psi. The NBAS has a density of 1.05 g/cm3, viscosity of 1.47 cP, and surface tension of 32 dynes/cm at room temperature. The corrosion rate of the developed system was 0.03 lb/ft2, which is acceptable according to oil and gas industry best practices. Removal experiments showed that the filter cake was completely removed from the core samples. For Berea sandstone, 100% of the permeability was regained, while the retained permeability for Indiana limestone was 122.5%, confirming the complete removal of external and internal filter cake as well as core samples stimulation. The new acid system can be considered as an efficient solution for oil-based filter cake removal that is biodegradable and cost-effective, where the reservoir permeability can be regained in one-stage only.

Well Clean-Up Using a Combined Thermochemical/Chelating Agent Fluids

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Chelating Agent ◽  
Drilling Fluids ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Different Types ◽  
Cake Removal

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.

Insight into Secondary Posterior Formation Damage During Barite Filter Cake Removal in Calcite Formations

2020 ◽  
Author(s):  
Jaber B. Al Jaberi ◽  
Badr S. Bageri ◽  
Assad Barri ◽  
Abdulrauf Adebayo ◽  
Shirish Patil ◽  
...  
Keyword(s):  
Filter Cake ◽  
Formation Damage ◽  
Insight Into ◽  
Cake Removal

scholarly journals Highly efficient removal of ammonia nitrogen from wastewater by dielectrophoresis-enhanced adsorption

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5001 ◽  
Author(s):  
Dongyang Liu ◽  
Chenyang Cui ◽  
Yanhong Wu ◽  
Huiying Chen ◽  
Junfeng Geng ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Ammonia Nitrogen ◽  
Optimal Operation ◽  
New Method ◽  
Discharge Criterion ◽  
Efficient Removal ◽  
Metal Mesh ◽  
Emission Standard ◽  
New Approach ◽  
Enhanced Adsorption

A new approach, based on dielectrophoresis (DEP), was developed in this work to enhance traditional adsorption for the removal of ammonia nitrogen (NH3-N) from wastewater. The factors that affected the removal efficiency were systematically investigated, which allowed us to determine optimal operation parameters. With this new method we found that the removal efficiency was significantly improved from 66.7% by adsorption only to 95% by adsorption-DEP using titanium metal mesh as electrodes of the DEP and zeolite as the absorbent material. In addition, the dosage of the absorbent/zeolite and the processing time needed for the removal were greatly reduced after the introduction of DEP into the process. In addition, a very low discharge concentration (C, 1.5 mg/L) of NH3-N was achieved by the new method, which well met the discharge criterion of C < 8 mg/L (the emission standard of pollutants for rare earth industry in China).

Removal of Rotenone from Contaminated Water Using Molecularly Imprinted Polymeric Microspheres

2011 ◽  
Vol 71-78 ◽  
pp. 1425-1428
Author(s):  
Kai Cheng Zhang ◽  
Si Ying Zhao ◽  
Ming Yang
Keyword(s):  
Removal Efficiency ◽  
New Method ◽  
Selective Recognition ◽  
Contaminated Water ◽  
Polymeric Microspheres ◽  
Molecularly Imprinted ◽  
Recognition Ability ◽  
Polymerization Method

A new method of removing rotenone from contaminated water using molecularly imprinted polymeric microspheres (MIPMs) is described. The MIPMs were prepared by the emulsifier-free polymerization method. The removal efficiency and selective recognition ability of the MIPMs were studied. The highest removal efficiency was observed at pH = 8. Moreover, the MIPMs can be re-used for at least 10 times without losing any removal efficiency. The MIPMs provided a selective, simple, reliable and practicable solution to remove rotenone from contaminated water.

Chelating Agent for Uniform Filter Cake Removal in Horizontal and Multilateral Wells: Laboratory Analysis and Formation Damage Diagnosis

2015 ◽  
Author(s):  
Hussain Al-Ibrahim ◽  
Tariq AlMubarak ◽  
Majed Almubarak ◽  
Peter Osode ◽  
Mohammed Bataweel ◽  
...  
Keyword(s):  
Filter Cake ◽  
Chelating Agent ◽  
Laboratory Analysis ◽  
Formation Damage ◽  
Damage Diagnosis ◽  
Cake Removal
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