Carbon Dioxide Corrosion and Corrosion Prevention of Oil Well Cement Paste Matrix in Deep Wells

2014 ◽  
Vol 692 ◽  
pp. 433-438 ◽  
Author(s):  
Jing Fu Zhang ◽  
Jin Long Yang ◽  
Kai Liu ◽  
Bo Wang ◽  
Rui Xue Hou
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Cement Paste ◽  
Oil Wells ◽  
Oil Well ◽  
Cement Slurry ◽  
Corrosion Prevention ◽  
Oil Well Cement ◽  
Oil Well Cement Paste ◽  
Well Cement

Carbon dioxide CO2could corrode the oil well cement paste matrix under agreeable moisture and pressure condition in deep oil wells, which could decrease the compressive strength and damage the annular seal reliability of cement paste matrix. The problem of oil well cement paste matrix corrosion by CO2was researched in the paper for obtain the feasible corrosion prevention technical measures. The microstructure and compressive strength of corroded cement paste matrix were examined by scanning electron microscopeSEMand strength test instrument etc. under different corrosion conditions. The mechanism and effect law of corrosion on oil well cement paste matrix by CO2were analyzed. And the suitable method to protect CO2corrosion in deep oil wells was explored. The results show that the corrosion mechanism of cement paste matrix by CO2was that the wetting phase CO2could generate chemical reaction with original hydration products produced from cement hydration, which CaCO3were developed and the original composition and microstructure of cement paste matrix were destroyed. The compressive strength of corrosion cement paste matrix always was lower than that of un-corrosion cement paste matrix. The compressive strength of corrosion cement paste matrix decreased with increase of curing temperature and differential pressure. The corroded degree of cement paste matrix was intimately related with the compositions of cement slurry. Developing and design anti-corrosive cement slurry should base on effectively improving the compact degree and original strength of cement paste matrix. The compounding additive R designed in the paper could effectively improve the anti-corrosive ability of cement slurry.

Research on Produced Fluid Corrosion Resistance Oil Well Cement Paste System in Adjustment Well

2016 ◽  
Vol 847 ◽  
pp. 451-455
Author(s):  
Jing Fu Zhang ◽  
Jun Dong Chen ◽  
Yu Wang ◽  
Ying Bo Lv
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Cement Paste ◽  
Oil Recovery ◽  
Oil Well ◽  
Laboratory Equipment ◽  
Oil Well Cement ◽  
Oil Well Cement Paste ◽  
Well Cement ◽  
Corrosion Time

To design oil well cement paste system and ensure well cementation quality of adjustment well in work area of tertiary oil recovery (EOR), the composition, microstructure and strength of cement paste matrix eroded by producing water were tested and studied by HTHP Curing Chamber, HTHP corrosion tester, X-ray diffraction, scanning electron microscope (SEM), universal testing compressor and some other laboratory equipment according to the condition that producing water contains sulfate (SO42-) and bicarbonate (HCO3-). The corrosion law and mechanism of oil well cement paste matrix were analyzed. The problem for designing corrosion resistance oil well cement paste system was investigated. The corrosion law and mechanism of oil well cement paste matrix by SO42- and HCO3- were raised. The corrosion resistant oil well cement paste system was designed, which was suitable to the adjustment well in area of EOR in Daqing. The results show that the compositions of cement paste matrix changed after corrosion by SO42- and HCO3- for a long term. The secondary gypsum, ettringite and calcite were produced, which changed the microstructures and declined the compressive strength of cement paste matrix. The change degree of compressive strength of cement paste matrix was affected by corrosion media concentration, corrosion time and other conditions. The higher concentration of corrosion media and the longer of corrosion time were, the greater decline of cement strength occurred. The formula of corrosion resistance oil well cement paste system was designed, for which the high sulfate resistant cement as architectural substrate and the PZW as admixtures were used to improve the strength and penetration resistance ability of cement.

scholarly journals Effects of confinement pressure on the mechanical behavior of an oil well cement paste

2021 ◽  
pp. 109769
Author(s):  
Victor Nogueira Lima ◽  
Flávio de Andrade Silva ◽  
Hans Joakim Skadsem ◽  
Katherine Beltrán-Jiménez ◽  
Jonas Kristoffer Sunde
Keyword(s):  
Mechanical Behavior ◽  
Cement Paste ◽  
Oil Well ◽  
Confinement Pressure ◽  
Oil Well Cement ◽  
Oil Well Cement Paste ◽  
Well Cement

scholarly journals Effect of Acid Activation-Hydrophilic-Modified Sepiolite on Comprehensive Properties of Oil-Well Cement

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yihang Zhang ◽  
Miao He ◽  
Mingbiao Xu ◽  
Peng Xu
Keyword(s):  
Cement Paste ◽  
Oil Well ◽  
Acid Activation ◽  
Cement Slurry ◽  
Comprehensive Properties ◽  
Oil Well Cement ◽  
Before And After ◽  
Sepiolite Fiber ◽  
Well Cement ◽  
Agent Treatment

In this paper, sepiolite was treated by acid activation, coupling agent treatment, and sulfonation modification. The purpose of this study was to explore the changes in the fluidity and mechanical properties of sepiolite cement slurry before and after modification. Therefore, the comprehensive properties of unmodified sepiolite fiber (HPS) and acid activation-coupling agent treatment-sulfonated sepiolite fiber (S-O-H-HPS) in oil-well cement slurry were evaluated. FT-IR and microscopic mechanism of cement paste fracture surface before and after sepiolite modification were analyzed. The results showed that HPS can effectively improve the toughness of cement paste, but when the content of HPS was more than 1%, the fluidity of cement paste deteriorated sharply and the compressive strength decreased gradually. The addition of S-O-H-HPS can significantly improve the fluidity and stability of HPS slurry. Without affecting the compressive strength, it can effectively improve the flexural strength and impact strength and reduce the elastic modulus of cement paste. The mechanism analysis showed that S-O-H-HPS can not only form network structure in cement paste but also improve the toughness of cement paste by forming a bridge. This also explains why the strength of S-O-H-HPS cement paste does not decrease significantly with the increase of S-O-H-HPS.

Development and Change of Compressive Strength for Class G Oil Well Cement under High Temperature

2014 ◽  
Vol 941-944 ◽  
pp. 1441-1444 ◽  
Author(s):  
Jing Fu Zhang ◽  
Kai Liu ◽  
Rui Xue Hou ◽  
Bo Wang ◽  
Jin Long Yang
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Initial Period ◽  
Strength Development ◽  
Oil Well ◽  
Curing Time ◽  
Cement Slurry ◽  
Critical Temperatures ◽  
Oil Well Cement ◽  
Well Cement

The compressive strength of oil well cement would be damaged by high temperature in deep oil wells, which was caused by the obvious change of the components and microstructure of cement hydration products. The adaptability of common oil well cement for cementing under higher temperatures was confined by above reasons. Characteristics of development and change of compressive strength of Class G oil well cement were studied under different temperatures by using Static Gel Strength Analyzer and High Temperature-High Pressure curing chamber. The influence law of temperature and silica sands on compressive strength was analyzed. The results showed that the critical temperatures at which the compressive strength begun to decline were about 110°C and 150°C respectively; The compressive strength increased with curing time during the initial period and would reduced after it reached a certain value when temperature exceeded 110°C; For cement with silica sands, the compressive strength development trend was in the shape of two-stage form with increase of curing time within the range of 110~150°C, but for 160~200°C temperature range the development form was in the shape of single stage; The reasonable amounts of silica sands which would be added to cement slurry to enhance the compressive strength of hardening paste were determined to be 30%~40%.

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