Acidizing Sandstone Reservoirs Using Fines Control Acid

Ji, Qin; Zhou, Lijun; Nasr‐El‐Din, Hisham A.

doi:10.2118/169395-ms

Cited by 8 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This area is mainly damaged during drilling, production and completion operations, resulting in clay swelling, fines migration, drilling fluid invasion and deposition of scale during production (Al-Harthy 2008/2009. Therefore, the removal of formation damage is the main goal of sandstone and carbonate acidizing (Ji et al 2014). Thus, the original permeability of the formation can be restored or enhanced by creating new pore spaces.…”

Section: Introductionmentioning

confidence: 99%

Investigation of change in different properties of sandstone and dolomite samples during matrix acidizing using chelating agents

Shafiq

Mahmud

Zahoor

et al. 2019

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

Properties of rock, such as effective porosity, permeability and pore size distribution (PSD), are generally referred to as petrophysical properties. These properties are among the most significant for reservoir evaluation. Acid stimulation treatments are usually used in sandstones to mitigate the impact of formation damage, with the aim of restoring or enhancing the natural matrix permeability and consequently boosting the well productivity. Hydrochloric acid (HCl) is commonly used in the preflush stage to remove calcium and other metal ions, preventing the development of calcium fluoride (CaF 2) and other silicate precipitates that could block the pore throats, while an acid mixture (HF-HCl combination) is usually preferred as the main stimulation fluid for the removal of quartz and remaining metal ions. However, sometimes the application of these acids can lead to other problems, including fast reactions, corrosion of pipes, environmental hazards, precipitation reactions and formation damage due to the incompatibility of HCl with clay minerals, so chelating agents have been proposed as an alternative for matrix stimulation fluids. In this study, three different chelating agents, ethylenediaminetetraacetic acid (EDTA), N-(2-hydroxyethyl) ethylenediamine-N,N′,N′-triacetic acid (HEDTA) and N-acetyl-l-glutamic acid (GLDA), have been used to stimulate Berea sandstone, Colton tight sandstone and Guelph dolomite samples. Core flood experiments were conducted on 1.5 × 3 (in 2) core plugs, at a temperature below 180 °F. A slow injection rate of (1-0.5 cc/min) was chosen for the treatment fluid, promoting the dissolution of ions by increasing the contact time between the fluid and the rock. Furthermore, nuclear magnetic resonance, wettability and micro-computed tomography (CT scan) analyses were employed to evaluate the effect of the acid treatment on formation properties such as porosity, PSD, pore topology, wettability and pore structure. After exposing the samples to HEDTA, large wormholes were detected in their pore network, demonstrating that HEDTA has the highest potential to create new pore spaces when compared to GLDA and EDTA when reacted with both types of samples.

show abstract

Section: Introductionmentioning

confidence: 99%

Investigation of change in different properties of sandstone and dolomite samples during matrix acidizing using chelating agents

Shafiq

Mahmud

Zahoor

et al. 2019

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

show abstract

“…For sandstone reservoirs, acidisation is performed in three steps: preflush, main flush and after flush [83]. In practice, at the preflush stage, HCL has been used for the dissolution of carbonates and positive ions (e.g., [83,[99][100][101]); nonetheless, its effectiveness is inconsistent and there are reported incidences of damages [102]. To circumvent this, it is possible to blend HCL with other chemicals to neutralise its adverse effects.…”

Section: Acidisation-tight Reservoirsmentioning

confidence: 99%

Production from Unconventional Petroleum Reservoirs: Précis of Stimulation Techniques and Fluid Systems

Eshiet¹

2022

Emerging Technologies in Hydraulic Fracturing and Gas Flow Modelling

View full text Add to dashboard Cite

An overview of the different categories of unconventional oil and gas reservoirs, and corresponding stimulation techniques appropriate for them is examined. Three main groups of unconventional oil and gas formations are appraised: heavy oil, oil shale and tight reservoirs. The scope of stimulation methods applicable to heavy oil reservoirs is limited. This kind of formation contains characteristic high-viscous hydrocarbons and are produced majorly by cold production and thermal stimulation. On the other hand, a wider range of stimulation methods are successfully used to produce tight and oil shales formations. For oil shales, these include drilling horizontal wells as substitutes to vertical wells, hydraulic fracturing, surfactant treatment, water imbibition, thermal treatment and acidisation; whilst for tight formations, these include hydraulic fracturing, surfactant treatment, water imbibition, acidisation and the application of electro-kinetics. Fracturing fluid systems are integral to the implementation of most stimulation operations and are evaluated herein under the following groups: water-based, oil-based, foam-based and acid-based. The most commonly used fracturing fluids are water based, albeit there are several instances where other types of fluids or combination of fluids are more suitable based on factors such as formation sensitivity, costs, wettability, rock solubility, surface tension, capillarity, viscosity, density, rheology and reactivity.

show abstract

A preliminary screening and characterization of suitable acids for sandstone matrix acidizing technique: a comprehensive review

Leong

Mahmud

2018

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

Matrix acidizing is a broadly developed technique in sandstone stimulation to improve the permeability and porosity of a bottom-hole well. The most popular acid used is mud acid (HF-HCl). It is a mixture of hydrofluoric acid and hydrochloric acid. However, one of the conventional problems in sandstone acidizing is that mud acid faces significant issues at high temperature such as rapid rate of reaction, resulting in early acid consumption. This downside has given a negative impact to sandstone acidizing as it will result in not only permeability reduction, but can even extend to acid treatment failure. So, the aim of this study is to provide a preliminary screening and comparison of different acids based on the literature to optimize the acid selection, and targeting various temperatures of sandstone environment. This paper has comprehensively reviewed the experimental works using different acids to understand the chemical reactions and transport properties of acid in sandstone environment. The results obtained indicated that fluoroboric acid (HBF 4) could be useful in enhancing the sandstone acidizing process, although more studies are still required to consolidate this conclusion. HBF 4 is well known as a low damaging acid for sandstone acidizing due to its slow hydrolytic reaction to produce HF. This would allow deeper penetration of the acid into the sandstone formation at a slower rate, resulting in higher porosity and permeability enhancement. Nevertheless, little is known about the effective temperature working range for a successful treatment. Considering the pros and cons of different acids, particularly those which are associated with HF and HBF 4 , it is recommended to perform a comprehensive analysis to determine the optimum temperature range and effective working window for sandstone acidizing before treatment operation. Prior to sandstone acid stimulation, it is essential to predict the feasibility of acid selected by integrating the effects of temperature, acid concentration and injection rate. Therefore, this manuscript has thrown light into the research significance of further studies.

show abstract

Acidizing Sandstone Reservoirs Using Fines Control Acid

Cited by 8 publications

References 13 publications

Investigation of change in different properties of sandstone and dolomite samples during matrix acidizing using chelating agents

Investigation of change in different properties of sandstone and dolomite samples during matrix acidizing using chelating agents

Production from Unconventional Petroleum Reservoirs: Précis of Stimulation Techniques and Fluid Systems

A preliminary screening and characterization of suitable acids for sandstone matrix acidizing technique: a comprehensive review

Contact Info

Product

Resources

About