Numerical Modeling of Gas Migration through Cement Sheath and Microannulus

ACS Omega ◽  
2021 ◽  
Author(s):  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Murtada S. Aljawad ◽  
Catalin Teodoriu
Keyword(s):  
Numerical Modeling ◽  
Gas Migration ◽  
Cement Sheath

Numerical Modeling of the Gas Migration Test at the Grimsel Test Site (Switzerland)

2008 ◽  
Vol 164 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Rainer Senger ◽  
Bill Lanyon ◽  
Paul Marschall ◽  
Stratis Vomvoris ◽  
Ai Fujiwara
Keyword(s):  
Numerical Modeling ◽  
Test Site ◽  
Gas Migration ◽  
Migration Test ◽  
Grimsel Test Site

scholarly journals Recipe of Lightweight Slurry with High Early Strength of the Resultant Cement Sheath

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1583 ◽  
Author(s):  
Marcin Kremieniewski
Keyword(s):  
Mechanical Performance ◽  
Bonding Time ◽  
Gas Migration ◽  
Cement Slurry ◽  
Well Drilling ◽  
Filling Materials ◽  
Cement Sheath ◽  
Reliable Knowledge ◽  
Short Time ◽  
Geophysical Measurements

Admixtures of mineral or waste filling materials are used to reduce slurry density. However, the sheath made of lightweight cement slurry has low mechanical performance at the initial bonding time. The required strength is achieved later. This is the main problem when evaluating the cement bond logging. The waiting time for geophysical measurements after injecting and bonding of cement is nowadays increasingly shortened. This is forced by economic factors. Too early geophysical measurements may result in obtaining a false indication of the cement bond logging. The lack of cement or partial bonding, despite the presence of slurry in the annular space is then found. The slurry developed by the author achieves high compressive strength after a short bonding time. Reducing the amount of water in the slurry resulted in a lowered filtration value. This is important in preventing gas migration after the cementing. The designed slurry also reaches the value of 3.5 MPa in a short time. This allows for an earlier commencement of a well drilling. The use of said slurry improves the effectiveness of the well sealing and makes it possible to obtain a reliable knowledge of the bond logging.

scholarly journals Effect of Cleaning the Annular Space on the Adhesion of the Cement Sheath to the Rock

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5187
Author(s):  
Marcin Kremieniewski ◽  
Sławomir Błaż ◽  
Stanisław Stryczek ◽  
Rafał Wiśniowski ◽  
Andrzej Gonet
Keyword(s):  
Drilling Fluid ◽  
Research Work ◽  
Rock Surface ◽  
Gas Flows ◽  
Gas Migration ◽  
Test Results ◽  
Annular Space ◽  
Rock Formation ◽  
Mud Cake ◽  
Cement Sheath

Drilling boreholes in gas zones and in zones with the possibility of migration or gas exhalation requires a high index of well tightness. An important parameter determining the effectiveness of sealing the annular space is the adhesion of the cement sheath to the rock formation. Low values of adhesion of the cement sheath to the rock formation and to the casing surface result in the formation of uncontrolled gas flows. The lack of adhesion also reduces the stabilization of the pipe column. To obtain the required adhesion, the annular space should be properly cleaned. Thorough removal of filter cake from the drilling fluid increases adhesion and reduces gas migration from the annular space. Therefore, in this work, the authors focus on determining the effect of cleaning the annular space on the adhesion of the cement sheath to the rock formation. The results of the research work allow for further research on the modification of spacers and cement slurries in order to obtain the required increase in adhesion. The article presents the issues related to the preparation of the borehole for cementing by appropriate cleaning of the rock formation from the residue of the mud cake. During the implementation of the works, tests of cleaning the rock surface are performed. The obtained results are correlated with the results of adhesion on the rock–cement sheath cleaned of the wash mud cake contact. When analyzing the obtained test results, a relationship is found between the cleaning of the rock surface and the adhesion of the cement sheath to it.

scholarly journals Possibilities of Limiting Migration of Natural Gas in Boreholes in the Context of Laboratory Studies

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4251
Author(s):  
Marcin Kremieniewski ◽  
Rafał Wiśniowski ◽  
Stanisław Stryczek ◽  
Grzegorz Orłowicz
Keyword(s):  
Structural Strength ◽  
Oil Industry ◽  
Hardened Cement ◽  
Gas Migration ◽  
Technological Parameters ◽  
Cement Slurry ◽  
Cement Sheath ◽  
Selection Of

Gas migration through fresh and hardened cement slurry is an ongoing problem in the oil industry. In order to eliminate this unfavourable phenomenon, research is being conducted on new compositions of slurries for gas wells. The article presents the results of research for slurries with low and high resistance to gas migration. The proper selection of the quantity and quality of components makes it possible to design slurry with the required static structural strength values. In addition, the cement sheath of such anti-migration slurry has low porosity and a very low proportion of large pore spaces. Additionally, the mechanical parameters do not decrease during long-term deposition in borehole-like conditions. By obtaining these results, it was possible to design slurry whose cement sheath has high corrosion resistance. The new slurry has a lower water-cement ratio. Additionally, GS anti-migration copolymer, anti-filter additive and latex are used. The presence of n-SiO2 aqueous solution and microcement allows for sealing the microstructure of the hardened cement slurry. Such modifications significantly improve the technological parameters of the cement slurry and the cement coat formed from it.

Mud-Removal Efficiency Boost by Engineered Scrubbing Spacer in Cementing Operations at Caspian Sea

2021 ◽  
Author(s):  
Amanmammet Bugrayev ◽  
Ravindra Kumar Singh ◽  
Svetlana Nafikova ◽  
Ilshat Akhmetzianov ◽  
Guvanch Gurbanov ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Successful Implementation ◽  
Gas Migration ◽  
Negative Consequences ◽  
Well Integrity ◽  
Annular Gap ◽  
Challenging Environment ◽  
Zonal Isolation ◽  
Cement Sheath

Abstract Long-term well integrity and zonal isolation are the ultimate objectives for cementing in the well construction process. Effective mud removal plays an essential role in obtaining competent zonal isolation and hence should not be overlooked and underestimated. The negative consequences of poor mud removal can lead to microannulus, channeling, or gas migration, which might require costly time-consuming remediation. The conventional approach of optimizing spacers based on chemical interactions with the mud layer does not always yield desired results and, thus, demanding further improvement. In this paper we discuss the approach taken to boost the mud removal efficiency by implementing an innovative engineered scrubbing spacer containing fibers in a challenging environment, resulting in notable improvement in long-term cement sheath integrity. The engineered scrubbing fibers were thoroughly tested in the laboratory to ensure spacer stability and efficiency. The new spacer with an additional scrubbing capability was introduced to one of the major operators on the Caspian shelf and after successful implementation, it has now been used on more than 20 cementing operations. Scrubbing fibers concentration was optimized through thorough laboratory testing covering flowability, dispersibility, and mud removal efficiency; later, it was applied on most of the cement operations, including 4½-in. liners characterized by a very narrow annular gap across the hanger sections. Cement evaluation log results from those cementing operations demonstrated an improvement in mud removal efficiency, suggesting no issues associated with microannulus, channeling, or gas migration, thus confirming the effectiveness of the newly implemented engineered scrubbing spacer. The typical challenges associated with meeting the zonal isolation requirement on one of the offshore fields of the Caspian shelf, and the success of the approach taken to overcome those challenges by implementing the new engineered scrubbing spacer are discussed. The comparison of cement bond evaluation log results of the jobs where conventional spacer systems were used vs. those where the spacer with scrubbing capability was used are also presented, demonstrating the clear difference and improvement.

Sign in / Sign up

Export Citation Format

Share Document