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Collaborating Authors
Bonding Mechanism of Zonal Isolation Materials to Clean and Rusted Casing
Kamali, Mohammadreza (Department of Energy and Petroleum Engineering, University of Stavanger (Corresponding author)) | Khalifeh, Mahmoud (Department of Energy and Petroleum Engineering, University of Stavanger) | Saasen, Arild (Department of Energy and Petroleum Engineering, University of Stavanger)
Summary In oil and gas and geothermal well construction, a cementitious material is pumped in the wellbore to provide zonal isolation and support the casing during the life cycle of the well. Thus, the cementitious barrier materials must be durable in terms of chemical and mechanical properties and have chemical compatibility with casing pipe. The complex region of casing-cement interface is considered a key parameter to fulfill long-term zonal isolation. This interface must be chemically stable and impermeable to block unwanted formation fluid communication. Shortcomings of conventional Portland cement under operational conditions and increasing sensitivity to its carbon footprint are motivations for a green alternative. Bond strength and sealability of cement with steel surface have been measured previously. But few research works cover surface characterization and morphological analysis of barrier materials and the connected steel surface. This study provides a full picture of selected alternative materials in terms of shear bond strength, hydraulic sealability, and interface morphology analysis of the materials. Materials include API Class G cement, an industrial expansive cement, noncement-based pozzolanic material, geopolymer, and thermosetting resin. Also, clean and rusted steels were considered as a representative for the casing pipe in the field. The samples were prepared under elevated pressure and temperature. The results proved that higher shear bond strength is not an indication of good sealability, and the ingredients used to mix slurries have a critical role in the structure of the interfacial zone between casing and barrier material.
- Europe > Norway (0.68)
- North America > United States > Texas (0.28)
- Research Report > New Finding (0.69)
- Research Report > Experimental Study (0.46)
Experimental Evaluation of the Effect of Temperature on the Mechanical Properties of Setting Materials for Well Integrity
Ogienagbon, Adijat (Department of Energy and Petroleum Engineering, University of Stavanger, Norway (Corresponding author)) | Khalifeh, Mahmoud (Department of Energy and Petroleum Engineering, University of Stavanger, Norway)
Summary A fundamental understanding of the mechanical properties of zonal isolation materials is important for predicting well integrity during well operation conditions. Conventionally, the mechanical properties of zonal isolation materials are tested at ambient temperature using uniaxial testing. This study examined the mechanical properties of alternative zonal isolation materials such as rock-based geopolymer, thermosetting resin, and an industrial class expansive cement under realistic well conditions by triaxial testing. Mechanical properties such as Young’s modulus, Poisson’s ratio, cohesive strength, friction angle, and compressive strength of these materials at 30 and 90°C were compared. The effect of confining pressure on the mechanical properties of the materials was also examined. The findings of this study show that all selected materials possess compressive strength at 30 and 90°C and that the compressive strength of all the selected materials is strongly impacted by temperature and confining pressure. The Young’s modulus of all the selected materials was unaffected by confining pressure, while only the Young’s modulus of thermosetting resin was sensitive to temperature. The influence of temperature on the Poisson’s ratio varied from one material to another. In addition, when the test temperature increased, the friction angle of neat Class G and geopolymer decreased.
- Europe > Norway (0.68)
- North America > United States > Texas (0.28)
- North America > United States > California (0.28)
- Europe > United Kingdom > Scotland (0.28)
Abstract Primary well cementing is performed to isolate annular space behind casing, protect casing from corrosive downhole fluids, holding casing in place and maintain well integrity. To fulfill these requirements, the desired barrier material should long last in the wellbore during the life cycle of well. Some limitations have been observed and reported by operating companies and scientist have been stated and documented during many years. Hence, efforts are made to find alternative materials to Ordinary Portland Cement (OPC) or enhancing the performance of oil well cement. In this study, the rheological behavior and short-term mechanical properties of a commercial expansive oil well cement has been studied and compared with neat class G cement as the base case. The experiments were performed at equal conditions for the both cements. These tests include characterization of rheology profiles, static fluid-loss, and impact of pressure on pumping time of the cement slurries. In addition, mechanical properties of the cement systems after hardening were studied by testing uniaxial compressive strength, non-destructive sonic strength development, indirect tensile strength (Brazilian test) and flexibility of samples up to 14 days. Our results in laboratory scale showed that using industrial chemicals as additive improved the rheological properties of cement by controlling the fluid-loss and retarding thickening time of the slurry. In case of the mechanical properties of the expansive cement, tensile strength of the specimens did not change and lower ductility was noticed comparing to the neat class G cement, even though uniaxial compressive strength of the barrier material was increased.
- North America > United States (1.00)
- Europe > Norway (0.68)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Pennsylvania > Appalachian Basin > Marcellus Shale Formation (0.99)
- (3 more...)
One Step Closer to Replacing Portland Cement with Geopolymers for Oil Well Applications
Kamali, M. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Norway) | Khalifeh, M. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Norway) | Kverneland, J. (TotalEnergies, Stavanger, Norway) | Benmesbah, M. (TotalEnergies, Pau, France) | Delabroy, L. (AkerBP, Stavanger, Norway) | Middleton, R. (ConocoPhilips, Stavanger, Norway)
Abstract Inorganic geopolymers are typically composed of aluminosilicate-rich powders and alkali silicate solutions as hardeners. Once mixed, these geopolymers exhibit cement-like behavior. However, highly alkaline solutions raise HSE (Health, Safety, and Environment) concerns in field operations. This paper provides a comprehensive characterization of a "one-part" granite-based geopolymer for oilfield applications that eliminates the need for alkaline solutions. Exactly like to cement, only fresh water is required to mix the geopolymer. As the reference material, API neat Class G cement was used for comparison. The fluid properties in the liquid state, including viscosity, gel strength, static fluid-loss, and mechanical properties after solidification such as sonic strength development, uniaxial compressive strength, and tensile strength, were tested following API standards. The initial analysis indicated that the rock-based geopolymer may not require any dispersant if the ingredients are engineered properly. However, a limitation of the geopolymer is its short thickening time at elevated temperatures. The use of two candidate organic and inorganic retarders extended the pumping time, followed by solidification and strength development. The short-term mechanical properties of the one-part geopolymer were evaluated by curing samples under downhole condition up to 60 days, where the bottom-hole circulation temperature and the static temperatures were 50°C and 70°C, respectively. The mix design exhibits a rapid transition from gelation to hardening. The compressive strength of the solidified samples was 50% less than that of the neat Class G cement, but the material demonstrated 4 times more flexibility.
Abstract Generally, the expansion of cementitious materials has been regarded as a promising avenue for better sealability. The sealability performance of an expanding geopolymer is compared to an expansive commercial cement in terms of the shear bond strength and the hydraulic bond strength at curing conditions of 25°C and 34.5 bar. A Neat Class G and a neat geopolymer were characterized alongside its corresponding expansive versions. The impact of these expansive agents on cement and geopolymers is evaluated in terms of linear expansion using the annular ring test. In terms of its performance for P & A operation, the push-out test was used to characterize the shear bond strength between the casing-cement interfaces, whereas the hydraulic bond strength is measured with a custom-made setup which eliminates any pressure and thermal shocks. These materials were characterized in terms of its shear bond strength, hydraulic bond strength and linear expansion. The shear bond strength of Neat G and expansive cement were estimated to be 22.37 bar and 22.76 bar respectively. Whereas that of the neat geopolymer and expansive geopolymer were recorded at 7.47 bar and 10.14 bar respectively. On the basis of the hydraulic bond strength, expansive cement had the highest followed by expansive geopolymer. Both the neat recipes were observed to have the same values in terms of the hydraulic bond strength. This study reveals that geopolymers can be deployed as an alternative to Portland cement upon optimization.
- Materials > Construction Materials (1.00)
- Energy > Oil & Gas > Upstream (1.00)