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Collaborating Authors
cement formulation
Surfactant in Cement Slurry: Solution for the Problem of Incompatibility with Oil Based Mud
Bakhareva, Elizaveta (Schlumberger, Tyumen, Russia) | Sukhachev, Vasilii (Schlumberger, Tyumen, Russia) | Kolchanov, Petr (Schlumberger, Moscow, Russia) | Sozonov, Alexander (Schlumberger, Tyumen, Russia) | Zinovyeva, Anastasia (Schlumberger, Tyumen, Russia) | Olennikova, Olesya (Schlumberger, Tyumen, Russia) | Akhmetzianov, Ilshat (Schlumberger, Tyumen, Russia)
Summary The main well cementing objective is to provide complete isolation of the formations behind the casing. To achieve this goal, the drilling fluid (mud) must be completely displaced in the annulus by cement. Effective mud removal is ensured by properly selected densities and fluid rheological hierarchy. However, even with ideal compliance with this rules, the oil based drilling fluid may not be completely replaced in the annulus. In such a case, contact of incompatible liquids occurs: cement and oil based mud. This leads to the formation of a viscous mass, which can cause high friction pressure during cementing job. In this situation, the zonal isolation of the formations is violated, and expensive remedial cementing job may be required. One solution for such cases may be use of surfactants to modify the properties of cementing systems in order to improve the compatibility of the drilling mud and cement slurry system. This paper presents the results of study describing the possibilities of using various surfactants and their effectiveness when used in cement slurries. The surfactant selection to obtain rheological compatibility of the oil based mud and cement slurry system is theoretically justified. The main attention was paid to rheological compatibility assessment and influence of surfactants on cement slurry properties, such as compressive strength development and thickening time. In addition to the initial assessment of the cement slurry properties, tests were carried out to determine cleaning and invert emulsion ability. In the process of studying, an express method for assessing the compatibility of cement and drilling mud was proposed and used. The work has shown that surfactant addition to cement slurry improves rheological compatibility between the cement and drilling fluid. The dependence of the rheological compatibility experiment results and type of surfactant is found. Technical and experimental confirmation of possibility of well cementing without the use of a spacer, was obtained. The novelty of the work is methodological approach for compatibility assessment of surfactant in cement slurry and slurry with drilling fluid (mud). This approach includes express method to select best surfactants candidates for further evaluation. The results of this study potentially allow to abandon the use of spacer in well cementing process and improve the quality of well cementing.
- Asia (0.46)
- North America > United States (0.29)
- Europe > Norway > Norwegian Sea (0.24)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
Enhancing Wellbore Integrity for Well Subject to Fracturing: Improving Cement Sheath Flexibility and Ensuring Long-Term Cost-Effective Well Integrity - A Case Study
Ahmad, Syed Hamza (SPRINT Oil and Gas Services, Pakistan) | Ahmed, Syed Sharjeel (SPRINT Oil and Gas Services, Pakistan) | Anwar, Rameez (SPRINT Oil and Gas Services, Pakistan) | Yousaf, Arif (SPRINT Oil and Gas Services, Pakistan) | Nazir, Muhammad Irfan (Oil and Gas Development Company Limited, Pakistan) | Noor, Sameer Mustafa (Oil and Gas Development Company Limited, Pakistan) | Iqbal, Javed (Oil and Gas Development Company Limited, Pakistan) | Nauman, Summer (Oil and Gas Development Company Limited, Pakistan)
Abstract In Fracturing operations, the cement sheath is likely to be compromised due to mechanical stresses. This could lead to well integrity issues in the long-run. To maintain the well-bore integrity and sustainment of subject stresses throughout the life cycle of the well-bore, flexibility in the cement sheath placed behind the casing can be a differentiating factor, incrementing in the life cycle of the well-bore and reducing the risk of mechanical failure in case of well subjected to high-pressure stress cycles during the fracturing operation. Developing intraparticle flexibility in cement is challenging and involves altering the mechanical properties of set cement by adding flexible particles with an average particle size ranging from 100-400 microns and not greater than 500 microns. The flexible particles tend to improve the mechanical properties of set cement in terms of impact resistance, fracture toughness and to a lesser extent tensile strength. Depending upon the formation, additional properties in the cement slurries can be incorporated using Anti-gas migration, fluid loss control, Compressive strength enhancer, and expansion additive to prevent post-setting cement shrinkage and improve cement bonding between the cement-formation and cement-casing with time as the expansion takes place. This paper demonstrates the working principle and practical applications of engineered solutions for long-term well integrity challenges during post-job cyclic stresses in which flexible particles were incorporated to render the set cement properties. Designed cement exhibits more resistance to impact and improves its long-term integrity from severe static and dynamic stresses. The slurry system aims to yield low young modulus and high flexural strength. The technology is the appropriate solution in cases where the set cement is subjected to severe stresses during fracturing jobs. The technology was utilized in both 9-5/8โณ sections and 7โณ liner with flexible cement to achieve zonal isolation. Cement-designed properties were tested in the lab to confirm the desired young modulus (<6000 MPa) and poison's ratio properties. However, this paper will focus on job designing and execution of 7โณ liner jobs using flexible cement. The mechanical properties were plugged in to stress check simulator with planned mechanical cyclic stresses to confirm cement sheath integrity post-fracturing job. The well was subjected to a multi-stage (10-successive stage) fracturing operation with a maximum pressure of up to 3,700 psi in each stage and a pumping rate of 24 bpm (per stage), with cumulative fluid pumped= (2,104 bbl). The well was observed post frac and completion and no well-bore integrity issues were reported post fracturing job. The well was subjected to a multi-stage fracturing operation with a maximum pressure of upto 3,700 psi and a pumping rate of 24 bpm, with cumulative fluid pumped2,104 bbl. The well was observed post-frac and completion and no wellbore integrity issues were reported post-fracturing job. This approach improves wellbore integrity during fracturing operations by modifying the mechanical with the addition of flexible particles. This enhances the set cement's mechanical properties; Laboratory testing and simulations validate its effectiveness. Field application shows successful zonal isolation and no integrity issues post-fracturing.
- Asia (0.69)
- North America > United States > Texas (0.28)
Geopolymer for Low-Temperature Shallow Depth Cementing Applications
Agista, M. N. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Rogaland, Norway) | Gomado, F. D. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Rogaland, Norway) | Khalifeh, M. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Rogaland, Norway) | Saasen, A. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Rogaland, Norway) | Moreira, P. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Rogaland, Norway)
Abstract Shallow depth cementing is often faced with the challenges of low temperatures and weak formation strength. To handle this challenge, green alternative cementitious material, so-called geopolymer, is proposed as an alternative to Portland-based cement for this specific application. In this article, the potential of using low-density geopolymer, utilizing the water-extended approach, for low temperature shallow depth application is described. Despite its flexibility in operation and slurry design, water-extended slurry is often faced with challenges such as weaker strength, prolonged thickening time, excessive free fluid and increased risk of particle sedimentation. The objective is to reduce the particle size distribution of its precursors to increase its reactivity and performance in the water extended low-density geopolymer. Two granite-based geopolymer mix designs, a normal-density geopolymer design and a low-density design, are compared. Several tests assessing thickening time, rheology, and compressive strength are performed on both geopolymer materials. For the low-density slurry, higher liquid-to-solid ratio is used to extend the slurry. Different source of precursors with smaller particle size distribution are used as the approach to obtain stable low-density slurry for low temperature application. This approach modifies the rheology profile of the slurry and leads to a more rapid hardening, making it suitable for surface casing cementing applications. Prolonged thickening time issue is solved with the low-density geopolymer, allowing the slurry to have a shorter thickening time. Smaller particle size results in water adsorption capacity and increased reactivity of precursor. Moreover, the low-density geopolymer shows rapid strength development for a short period of observation of 7 days at low temperature. The result shows the potential of low-density geopolymer, utilizing a liquid extended approach, for low temperature surface casing cementing applications.
- South America > Brazil (0.46)
- Europe > Norway (0.29)
Mineralogical Characterization of Mature Oil Well Cement Pastes Exposed to Downhole Conditions for 30+ Years
Mello e Alvim, Thiago Monteiro (Universidade Federal do Rio de Janeiro) | Beltrรกn-Jimรฉnez, Katherine (Norwegian Research Centre) | Gardner, David J. (Norwegian Research Centre) | Toledo Filho, Romildo Dias (Universidade Federal do Rio de Janeiro) | Mendoza Reales, Oscar A. (Universidade Federal do Rio de Janeiro)
Abstract The objective of this work is to characterize the alteration on cement pastes exposed to 30+ years of natural ageing at downhole conditions. The cement samples used in this study were recovered from two production wells drilled in the Norwegian continental shelf completed in the late 1980's. Sandwich sections comprised of an inner and outer casing section with cement in between were recovered to surface prior to well abandonment. After recovery, cement samples were cut and studied to investigate signs of alteration and degradation. The characterization was performed using chemical and mineralogical characterization techniques such as: Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and X-Ray Fluorescence (XRF). Along with the two well cement samples, an additional class G cement, control sample, was produced and cured in control condition so that it could be used as a reference for a younger cement. The cement samples studied in this article were not exposed to aggressive agents such as CO2 and H2S either at downhole conditions or in the lab, therefore the main driver for alteration or degradation was ageing. The results indicate that after an exposure time frame comparable with the service life of an oil well at relatively low temperatures, the conditions did not induce significant chemical or mineralogical changes. When comparing the recovered samples with the control sample, the main alteration identified was the higher level of carbonation process. This process indicates natural ageing of the cement during the 40-year period that finally led to a reduction of strength. This work supports the understanding of the durability of well cement and well integrity. The results presented help to establish a base line and to identify the alteration and degradation due to ageing through the end of the wells production life and the start of the abandonment phase.
- South America > Brazil (0.47)
- Europe > Norway (0.28)
- Geology > Mineral (1.00)
- Geology > Geological Subdiscipline > Mineralogy (0.83)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Hod Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Hod Formation (0.99)
Quality Assurance on Annulus Isolation Under Well Cementing Uncommon Events โ Practical Approaches in Deepwater Wells
Moreira, R. P. (Petrobras, Rio de Janeiro - RJ, Brazil) | Ribeiro, D. B. (Petrobras, Macaรฉ - RJ, Brazil) | Lima, L. B. (Petrobras, Rio de Janeiro - RJ, Brazil) | Piedade, T. S. (Petrobras, Macaรฉ - RJ, Brazil)
Abstract Defining acceptable criteria for primary cementing operations has always been challenging. When unconventional events or conditions occur during the cement job, the potential impact on future well integrity shall be evaluated before proceeding further operations during well construction. This study aims to describe practical approaches on evaluating zonal isolation based on cementing design robustness and post job signature when such unconventional conditions are present in Brazilian deepwater wells. A large database for well casing cementing scenarios in Brazilian deepwater fields provides information to correlate and identify the most present cementing abnormalities and undesired well conditions prior to cementing and the quality of annular isolation through cement evaluation logs ran. The analysis, additionally to the operational normality evaluation, considers different scenarios such as the presence of extensive salt zones, low-fracture gradient formations, ballooning plastic formations and the different cementing strategies performed in each well. The data provides evidence that fluid losses and cementing hardware malfunction are the most common failure modes for annulus isolation in the deepwater wells analyzed. However, there are situations where these abnormalities do not interfere in cementing quality, and a more detailed analysis should be performed to identify if an impaired condition will occur. Two case studies detail the process, the first for salt zone cementing in pre-salt wells show that it is possible to identify the loss zone depth through job parameters, and the second case study for two-stage cementing in post-salt wells show that it is possible to identify impact on casing hardware malfunction. Although the common practice of cement evaluation under cementing abnormalities takes the running of logs to identify impact on zonal isolation, the approach here described consider an engineered analysis on the job parameters that may simplify the process safely and lead to cost reduction for casing cement quality assurance.
- South America > Brazil > Brazil > South Atlantic Ocean > Santos Basin (0.99)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Mississippi Canyon > Block 252 > Macondo Field > Macondo 252 Well (0.99)
Development of a Rock-Based Geopolymer for Well Abandonment Applications - Utilizing Brazilian Rock Precursors
da Silva, R. Ribeiro (Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil) | de Oliveira Freitas, J. C. (Department of Chemistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil) | Moreira, R. Peralta Muniz (Petrobras, Brazil) | Braga, R. Martins (Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil) | Khalifeh, M. (Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, Norway)
Abstract This article focuses on the development and characterization of one-part rock-based geopolymer slurries utilizing Brazilian rock precursors for well construction and plugging and abandonment applications (P&A). The study presents the fluid-state and solid-state properties of these geopolymers, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) to understand the precursors' microstructure and reaction level. The effect of temperature and pressure on compressive strength development was investigated. By altering these parameters, the study aimed to understand the impact of different environmental conditions on the strength development of the geopolymer material. Technological tests were performed according to API RP 10B-2. Compressive strength tests were conducted to determine early strength development and thickening time, and UCA tests were carried out. Post-curing, Retvied analysis through XRD was performed to examine microstructure and reactivity. Finally, fluid-state properties were also assessed, including thickening time and viscosity. The strength development of the geopolymers is observed to be time and temperature-dependent, as shown through ultrasonic strength data. The final product has a dense structure, and its long-term performance will require evaluation to determine its sealing capability and volume change as a barrier material. The research demonstrates the potential of rock-based geopolymers for well cementing and well abandonment applications using a Brazilian rock precursor.
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.34)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (1.00)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid management & disposal (1.00)
- Well Drilling > Casing and Cementing > Cement formulation (chemistry, properties) (1.00)
- (2 more...)
Correlating Shrinkage Behavior and Transit Time Development in Well Cement for Offshore Wells
Costa Carvalho, Carlos Pessanha (Petrobras) | Melo da Silva, Emilio Cesar Cavalcante (Petrobras) | Telles, Jose Claudio De Faria (Universidade Federal do Rio de Janeiro) | Simao, Cristina Aiex (Petrobras) | Tavares, Pedro Rocha (Petrobras) | Blanco, Ana Luiza Pessanha (Universidade Federal do Rio de Janeiro) | Toledo Filho, Romildo Dias (Universidade Federal do Rio de Janeiro) | de Siqueira, lolanda Scheibe (Universidade Federal do Rio de Janeiro) | Mello e Alvim, Thiago Monteiro (Universidade Federal do Rio de Janeiro)
Abstract Understanding cement shrinkage behavior in offshore well cement sheaths is crucial for assessing integrity and preventing potential issues. This study investigates the correlation between early strength development and shrinkage to assist in cement paste design. In this research, one cement paste was formulated with water-to-cement ratio of 0.36 and cured under different conditions, including temperatures of 40 ยฐC, 60 ยฐC and 80 ยฐC, and a pressure of 1.0 kpsi. The development of the cement pastes was analyzed using ultrasonic pulse velocity and volumetric shrinkage tests over a period of 90 hours. By employing specific markers of percolation in each test, the results were synchronized, enabling the correlation of data to better understand the evolution of shrinkage and its relationship to transit time. The results obtained from the experimental testing showed a clear correlation between the normalized evolutions of transit time and cement shrinkage for the 3 testing conditions. The findings of this study allow the practitioner to understand when and how shrinkage will occur, with respect to a routine test, the ultrasonic pulse velocity. The results can feed numerical models of early cement behavior. This will support better decisions about well operations to be performed during the wait-on-cement time and in the following days, improving its performance as a well barrier.
Ultimate Strength Reliability Analysis Applied to the Design of Cement Sheaths in Oil Wells
Estrela, Gabriela Alves (LACEO/COPPE/UFRJ) | de Sousa, Fernando Jorge Mendes (LACEO/COPPE/UFRJ) | Lopes, Guilherme Kronemberger (LACEO/COPPE/UFRJ) | Gonzaga e Silva, Ana Beatriz de Carvalho (NUMATS/COPPE/UFRJ) | de Andrade, Henrique Conde Carvalho (NUMATS/COPPE/UFRJ) | Rocha, Josรฉ Marcelo Silva (PETROBRAS) | Moreira, Rafael Peralta Muniz (PETROBRAS) | da Silva, Ingrid Ezechiello (PETROBRAS)
Abstract In offshore wells, cement sheaths are responsible for isolating the casing from the formation, protecting the latter from corrosion, and preventing fluid migrations that can cause severe blowouts in extreme situations. The most usual methodology applied in the structural evaluation of cement sheaths is deterministic, where characteristic values are employed to model material properties and loads. At the end of the analysis, stresses (or any other derived parameter) are compared to allowable limits. Although this design methodology is relatively simple, it doesn't consider uncertainties regarding material properties and loading conditions. Moreover, no information is provided concerning how far the structure is from failure. These issues can only be addressed using a statistical approach. In this way, this work aims to propose a reliability-based methodology to be applied to the design of cement sheaths. Using the FORM method and a structural analysis computer program (TENCIM-1D โ Toledo Filho et al. 2020), failure probabilities can be easily accessed with low computational costs. These values can then be compared to target failure probabilities specified in offshore standards. In addition, the FORM method can also improve the design quality, as one of its subproducts โ the derived importance factors โ may help to identify the properties and parameters that most contribute to the obtained failure probabilities. Therefore, these properties and parameters are the ones that need to be better described statistically, either through experiments to survey physical properties or through field measurements. The obtained results indicate the feasibility of the proposed methodology and the need to develop studies to determine the probability distributions, mean values and standard deviations of some physical properties and loads.
- South America > Brazil (0.70)
- North America > United States > Texas (0.46)
A Cutting-Edge Approach in Cement Testing for Carbon Capture and Storage Applications
Parrozza, Fabio (Eni S.p.A.) | Cracolici, Federico (Eni S.p.A.) | Farina, Daniele (Eni S.p.A.) | Iorio, Vanessa Silvia (Eni S.p.A.) | Dal Forno, Luca (Eni S.p.A.) | Bertoldi, Lucio (Eni S.p.A.) | Ravi, Kris (Montanuniversitรคt Leoben) | Prohaska, Michael (Montanuniversitรคt Leoben) | Hahn, Felix (Montanuniversitรคt Leoben) | Lebwohl, Stefan (Montanuniversitรคt Leoben)
Abstract Carbon Capture and Storage became of paramount importance in the global effort to reach carbon neutrality targets as it represents the most suitable technology for hard-to-abate industry emissions. One of the crucial challenges of CCS technologies is constituted by permanent CO2 placement in the selected geological storage site. To reach this target cement plays a fundamental role as it must provide good sealing between the well and the rock formations avoiding any possible leakage route. Standard laboratory procedures, such as API Specification RP 10, are used to investigate cement performance and properties after extended CO2 exposure in pressurized autoclaves at controlled pressure and temperature conditions. At the end of the exposure period, cement properties are finally evaluated through mechanical, chemical and mineralogical tests. Unfortunately, this test configuration takes a significant amount of time to reach the first results and does not provide any dynamics evolution of the CO2 carbonation front. Consequently, an innovative setup was designed to improve the quality of the cement-fluids interaction assessment. To better replicate downhole conditions, a cylindrical sandstone core is encapsulated by cement to represent inverted annular conditions. During a test, CO2 is radially injected through the sandstone core into the cement annulus, typically over a test duration of three months. An innovative in-situ test cell is developed that allows to retrieve real-time information about the evolution of the carbonation front from a CT-scanner, while the test is ongoing. In addition, CO2 consumption and system permeability measurement can also be measured under in-situ conditions. The newly developed in-situ test cell enables instant evaluation of CO2 effect on cement, without compromising sample integrity. Thus, new insights into this complex behaviour of cement/CO2 interactions have been gained.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.46)
- Geology > Geological Subdiscipline > Mineralogy (0.37)
Geopolymer for Oilfield Application: Scaling up Laboratory Test to Yard Test
Sazali, Y. A. (PETRONAS Research Sdn. Bhd.) | Riyanto, L. (PETRONAS Research Sdn. Bhd.) | Ebining, M. S. (PETRONAS Research Sdn. Bhd.) | Rahman, S. H. (PETRONAS Research Sdn. Bhd.) | Zulkarnain, N. N. (PETRONAS Research Sdn. Bhd.) | Kumar, A. K. (PETRONAS Carigali Sdn. Bhd.) | Lau, C. H. (PETRONAS Carigali Sdn. Bhd.)
Abstract The present paper describes applicability of geopolymers to oilfield use. As a completely new system in oilfield, one of the main concerns about geopolymer was compatibility with oilfield equipment. It is known that geopolymer system differs from a conventional cement by a composition of base fluid and a mixing order which leads to a question of capability of existing cementing equipment to handle the geopolymer slurries. In order to validate mixability and pumpability of geopolymer slurry, a yard test had been conducted in order to test geopolymer formulations with two densities, 15 and 16.5 pgg. The yard test proved that the geopolymer system could be mixed and pumped using conventional equipment in the batch mixing as well as in the on-the-fly pumping regimes. During the yard test the geopolymer formulations were pumped with a rate up to 6 bbl/min. Results showed that special attention should be paid to a base fluid preparation and HSE aspects of the mixing and pumping process. The articles discuss practical recommendation about geopolymer preparation and pumping. For the first time it was demonstrated that geopolymer systems could be mixed and pumped using conventional cementing equipment. All mixed geopolymer slurries tested according to the API RP 10B standard and demonstrated acceptable properties, including rheology, thickening time, compressive strength and fluid loss. In addition to that the paper suggests the draft of the quality control procedure for geopolymers used in oilfield.
- Asia (0.94)
- North America > United States > Texas (0.28)