Optimization and Field Test of a Chelating Acid System for Scaled Gas Wells in the Hechuan Gas Field

Qiang Li, Zhenzhong Fan, Qingwang Liu, Guohong Liu, Wenhai Ma, Junliang Li, Nan Li and Pingang Ma
Additional contact information
Qiang Li: Petroleum Engineering College, Northeast Petroleum University, Daqing 163318, China
Zhenzhong Fan: Petroleum Engineering College, Northeast Petroleum University, Daqing 163318, China
Qingwang Liu: Petroleum Engineering College, Northeast Petroleum University, Daqing 163318, China
Guohong Liu: Daqing Oilfield Production Engineering Research Instititute, Daqing 163453, China
Wenhai Ma: Daqing Oilfield Production Engineering Research Instititute, Daqing 163453, China
Junliang Li: Daqing Oilfield Production Engineering Research Instititute, Daqing 163453, China
Nan Li: Daqing Oilfield Production Engineering Research Instititute, Daqing 163453, China
Pingang Ma: Daqing Oilfield Production Engineering Research Instititute, Daqing 163453, China

Energies, 2021, vol. 14, issue 23, 1-16

Abstract: The Hechuan gas field is one of the tight gas reservoirs with the highest formation water salinity in China. The content of metal ions, such as calcium, magnesium, iron, and barium, is as high as 20 g/L. Severe scales in near-wellbore reservoir blocks the gas and liquid flow paths, affecting the normal production of gas wells. The analysis of scale samples shows that the scale compositions in the Hechuan gas field are complex, which are composed of calcium carbonate, calcium sulfate, barium sulfate, iron salt, silicate, and other inorganic scales. To dissolve these scales, 14 kinds of laboratory self-made chelating acids named AST-01 to AST-14, sequentially, were evaluated by the descaling rate, in which the chelating acid AST-01 was selected with a dissolution rate of 77.7%. Meanwhile, the optimal concentration and reaction time of AST-01 were investigated, and the concentrations of the corrosion inhibitor, the iron ion stabilizer, and surfactants were also optimized. Then, a chelating acid descaling formula was obtained, which was 15~20% of AST-01 chelating acid + 1.5~2.0% of corrosion inhibitor + 2.5% of iron ion stabilizer + 0.3% of drainage aid. A pilot field trial of this descaling formula was applied in a Hechuan X1 well. A remarkable result was obtained in that the shut-in tubing pressure recovery rate was increased by 14 times, the gas production was increased by 10 times, and the gas well resumed to produce continuously again.

Keywords: Hechuan gas field; carbonate and sulfate scales; chelating acid; descaling; high salinity (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/23/7959/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/23/7959/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:23:p:7959-:d:690351

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().