A Systematic Approach to Improve the Performance of Acid-Fracturing Treatments in Low-Pressure, Low-Temperature Wells

Kritzler, Torsten; Yaseen, M.; Dutta, Bapan K.; Chacon, E.

doi:10.2118/73746-ms

Cited by 5 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For that purpose, acid fracturing with high-rate nitrogen pumping is planned to aid flowback and ensure proper kick-off after the treatment. Kritzler et al (2002) has discussed acid fracturing energized with nitrogen to 60 to 70% foam quality as an optimum stimulation method for low-pressure, low-temperature carbonates; this helps bring about flowback and longer fracture propagation because of the retardation effect of energized acid.…”

Section: Ways Forwardmentioning

confidence: 99%

Experience of Carbonate Acidizing in the Challenging Environment of the Volga-Urals Region of Russia

Kayumov

Konchenko

Bairamov

et al. 2014

Day 1 Wed, February 26, 2014

View full text Add to dashboard Cite

The Volga-Urals basin is one of the largest oil-producing regions in Russia. Orenburg region is essential part of Volga-Urals basin and it represents most of the challenges encountered in the other parts of the basin. More than half the wells produce exclusively from carbonate formations and require periodic acidizing treatments to maintain economic production. Carbonate stimulation treatments are usually based on pumping of hydrochloric acid into the formation with use of special diverters to maximize zone coverage by acid treatment. Some of the formation properties in Volga-Urals basin create additional challenges for successful acidizing treatments, including significant reservoir pressure depletion, high water cut, formation heterogeneity with high-and low-permeability strikes, low reservoir temperature, crude with tendency for emulsion and sludge creation, and enormous thief zones created by previous acidizing treatments. In many cases, uncertainties in the formation properties make the stimulation more complex.Carbonate stimulation practices in the Orenburg region have continuously improved during the last 6 years. First, degradable balls and polymer self-diverting acid were introduced to improve zone coverage. Later, viscoelastic self-diverting acid was added to eliminate damage associated with the polymer, and a viscoelastic selective diverter was used to minimize the probability of an increase in water cut after the treatment. Finally, foam was placed as a diversion agent, with and without coiled tubing (CT), to account for reservoir pressure depletion and help in post-acidizing flowback. Many lessons were learned, resulting in recommendations for use of various technologies at different reservoir and wellbore conditions.In addition to the recommendations for technologies, a quality assurance and quality control (QAQC) standard was developed and implemented for acidizing treatments. Moreover, laboratory work such as core flow testing and proppant embedment tests has been undertaken to clarify post-treatment aspects.Most fields in the Orenburg region are old, which implies that quality of well candidates became worse from year to year. However, with continuous improvement in stimulation practices and rigorous quality control we manage to maintain production at economic level and even increase work scope compared with previous years. This paper presents the experience gained during the 6-year of acidizing treatments in Orenburg region with lessons learned, and best practices adopted.

show abstract

Section: Ways Forwardmentioning

confidence: 99%

Experience of Carbonate Acidizing in the Challenging Environment of the Volga-Urals Region of Russia

Kayumov

Konchenko

Bairamov

et al. 2014

Day 1 Wed, February 26, 2014

View full text Add to dashboard Cite

show abstract

“…However, due to the fact that most formations in the middle east are carbonate formations, acid fracturing is more common in these countries such as Bahrain and Saudi Arabia. [1][2][3][4][5] Therefore different challenges, such as corrosion of tubulars and increased fluid leak-off, have to be addressed.…”

Section: Acid Fracturing Backgroundmentioning

confidence: 99%

Recent Developments in High-Temperature Acidizing with Super 13Cr Completions: Laboratory Testing

Nasr‐El‐Din

Al-Khuraidah

Cassidy

2002

Proceedings of Abu Dhabi International Petroleum Exhibition and Conference

View full text Add to dashboard Cite

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractSaudi Arabia embarked on an aggressive development of new gas fields to meet the increasing demand for natural gas and gas condensate. Therefore, it became necessary to further develop gas reservoirs. However, the reservoirs presented challenging conditions such as temperatures up to 275ºF, H 2 S contents up to 10 mol% and CO 2 contents higher than 2 mol%. Previous completions utilized regular low-carbon steel (L-80 and C-95) metallurgy. Due to the nature of the reservoir conditions, these types of completion hardware could not be applied in areas where H 2 S content is very low and CO 2 is high. Super 13Cr completions have been proven to be reliable in these environments. However, Super 13Cr completions cannot tolerate the high acid concentrations (28 wt% HCl Acid) that are needed to acid fracture the tight carbonate formations available in Saudi Arabia. Therefore, a special acid blend and corrosion inhibitor package had to be developed to effectively stimulate the carbonate formation through these types of completions. This paper will present how the aforementioned problem was overcome by developing an acid blend using 15 wt% HCl and 9 wt% formic acid. Initial laboratory tests showed high corrosion rates for the Super 13Cr coupons when this acid formulation was applied. However, due to an intensive research effort, an effective corrosion inhibitor package was developed for Super 13Cr completions using this acid system. Several corrosion inhibitors and inhibitor aids were tested. Compatibility of various additives was conducted and corrosion tests were performed at bottom-hole conditions. As a conclusion, a new corrosion package was developed for Super 13Cr tubing. This package is compatible with reservoir fluids and other acid additives. In addition, it produces acceptable corrosion rates with no pitting.

show abstract

Mineral Cracking and Porosity Enhancement of Shale Through Acidizing

Sheng¹,

Khan²,

Cheng³

et al. 2019

Proceedings of the SPE/AAPG/SEG Asia Pacific Unconventional Resources Technology Conference

View full text Add to dashboard Cite

A Systematic Approach to Improve the Performance of Acid-Fracturing Treatments in Low-Pressure, Low-Temperature Wells

Cited by 5 publications

References 12 publications

Experience of Carbonate Acidizing in the Challenging Environment of the Volga-Urals Region of Russia

Experience of Carbonate Acidizing in the Challenging Environment of the Volga-Urals Region of Russia

Recent Developments in High-Temperature Acidizing with Super 13Cr Completions: Laboratory Testing

Mineral Cracking and Porosity Enhancement of Shale Through Acidizing

Contact Info

Product

Resources

About