Obtaining Zonal Isolation in Geothermal Wells

2021 ◽  
Author(s):  
Allam Putra Rachimillah ◽  
Cinto Azwar ◽  
Ambuj Johri ◽  
Ahmed Osman ◽  
Eric Tanoto
Keyword(s):  
Best Practices ◽  
Oil And Gas ◽  
Lessons Learned ◽  
Free Fluid ◽  
High Heating Rate ◽  
Lost Circulation ◽  
Geothermal Well ◽  
Geothermal Wells ◽  
Zonal Isolation ◽  
Primary Cementing

Abstract Cementing is one of the sequences in the drilling operations to isolate different geological zones and provide integrity for the life of the well. As compared with oil and gas wells, geothermal wells have unique challenges for cementing operations. Robust cementing design and appropriate best practices during the cementing operations are needed to achieve cementing objectives in geothermal wells. Primary cementing in geothermal wells generally relies on a few conventional methods: long string, liner-tieback, and two-stage methods. Each has challenges for primary cementing that will be analyzed, compared, and discussed in detail. Geothermal wells pose challenges of low fracture gradients and massive lost circulation due to numerous fractures, which often lead to a need for remedial cementing jobs such as squeeze cementing and lost circulation plugs. Special considerations for remedial cementing in geothermal wells are also discussed here. Primary cement design is critical to ensure long-term integrity of a geothermal well. The cement sheath must be able to withstand pressure and temperature cycles when steam is produced and resist corrosive reservoir fluids due to the presence of H2S and CO2. Any fluid trapped within the casing-casing annulus poses a risk of casing collapse due to expansion under high temperatures encountered during the production phase. With the high heating rate of the geothermal well, temperature prediction plays an important part in cement design. Free fluid sensitivity test and centralizer selection also play an important role in avoiding mud channeling as well as preventing the development of fluid pockets. Analysis and comparison of every method is described in detail to enable readers to choose the best approach. Massive lost circulation is very common in surface and intermediate sections of geothermal wells. On numerous occasions, treatment with conventional lost-circulation material (LCM) was unable to cure the losses, resulting in the placement of multiple cement plugs. An improved lost circulation plug design and execution method are introduced to control massive losses in a geothermal environment. In addition, the paper will present operational best practices and lessons learned from the authors’ experience with cementing in geothermal wells in Indonesia. Geothermal wells can be constructed in different ways by different operators. In light of this, an analysis of different cementing approaches has been conducted to ensure robust cement design and a fit-for-purpose cementing method. This paper will discuss the cementing design, equipment, recommendations, and best available practices for excellence in operational execution to achieve optimal long-life zonal isolation for a geothermal well.

Comparative experimental evaluation of drilling fluid contamination on shear bond strength at wellbore cement interfaces

2014 ◽  
Vol 11 (6) ◽  
pp. 597-604 ◽  
Author(s):  
Mileva Radonjic ◽  
Arome Oyibo
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Geothermal Wells ◽  
Sustained Casing Pressure ◽  
Zonal Isolation ◽  
Casing Pressure ◽  
The Impact

Wellbore cement has been used to provide well integrity through zonal isolation in oil and gas wells as well as geothermal wells. Failures of wellbore cement result from either or both: inadequate cleaning of the wellbore and inappropriate cement slurry design for a given field/operational application. Inadequate cementing can result in creation of fractures and microannuli, through which produced fluids can migrate to the surface, leading to environmental and economic issues such as sustained casing pressure, contamination of fresh water aquifers and, in some cases, well blowout. To achieve proper cementing, the drilling fluid should be completely displaced by the cement slurry, providing clean interfaces for effective bond. This is, however, hard to achieve in practice, which results in contaminated cement mixture and poor bonds at interfaces. This paper reports findings from the experimental investigation of the impact of drilling fluid contamination on the shear bond strength at the cement-formation and the cement-casing interfaces by testing different levels of contamination as well as contaminations of different nature (physical vs. chemical). Shear bond test and material characterization techniques were used to quantify the effect of drilling fluid contamination on the shear bond strength. The results show that drilling fluid contamination is detrimental to both cement-formation and cement-casing shear bond strength.

Breakthrough Cementing Technology for Enhanced Well Integrity in Myanmar Offshore Shallow Gas Well

2021 ◽  
Author(s):  
Yi Li ◽  
Mohammad Solim Ullah ◽  
Wu Chang Ai ◽  
Thirayu Khumtong ◽  
Kantaphon Temaismithi ◽  
...  
Keyword(s):  
Gas Migration ◽  
Negative Effects ◽  
Shallow Gas ◽  
Gas Well ◽  
Lost Circulation ◽  
Security Issues ◽  
Zonal Isolation ◽  
Primary Cementing ◽  
Fit For Purpose

Abstract In Myanmar offshore, a substantially promising gas reservoir was discovered, the objective of primary cementing is to achieve long term zonal isolation, as any gas migration to surface would cause production loss, as well as significant security issues. Remedial cementing work will cause costly non production time, while the result will be compromised. Shallow gas migration, lost circulation and mud removal, all these factors cause undesired negative effects for cementing design, While the objective is to provide a firm barrier and good zonal isolation, this paper will describe in details the cementing challenge, the methodology, and how the slurry parameter was designed and evaluated for a Fit-For-Purpose solution.

Deep Geothermal Well Construction Problems and Possible Solutions

2021 ◽  
Author(s):  
Mikhail Yakovlevich Gelfgat ◽  
Aleksandr Sergeevich Geraskin
Keyword(s):  
High Pressure ◽  
Geothermal Energy ◽  
Oil And Gas ◽  
Directional Drilling ◽  
Geothermal Well ◽  
Coiled Tubing ◽  
Deep Wells ◽  
Fluid Jets ◽  
Drilling Technology ◽  
Geothermal Wells

Abstract The geothermal energy is one of the most promising sources of electricity on the planet; it is available almost anywhere on the continents and resources are inexhaustible. The realization of these possibilities requires solving the problems of deep wells (6-10 km) construction, when the lower horizons are practically impermeable crystalline basement rocks. For effective use of the Earth's heat, bottomhole temperatures must be within 200-300°C. World experience of such deep wells construction is very limited, some examples are given in this work. Known schemes of geothermal energy application requires at least two wells construction - for cold fluid injection and superheated fluid production. The rock - circulating fluid heat exchange in the bottomhole requires drilling of inclined, horizontal, or multi-lateral boreholes and hydraulic fracturing application. Such technologies are widely used in the oil and gas fields, but not in crystalline rocks. The article presents an analysis of the prospects for the geothermal wells construction efficiency increasing by using modern directional drilling systems, drilling with casing, technologies for complications eliminating. The possibilities of using alternative hard rock drilling methods by enhancing the standard formation destruction with drill bits are discussed. These are hydraulic hammers, high-pressure abrasive and fluid jets, laser drilling. A fundamentally new plasma drilling technology is considered. The most serious limitation of alternative drilling prospects is the need of additional "supply lines" to the bottom: high-pressure fluid; electricity; a plasma forming agent, etc. In this regard, options are being considered for the development of continuous drill strings such as coiled tubing, umbilical, flexible composite systems like subsea pipelines. Some of technological solutions for deep geothermal wells construction, and implementation of petrothermal energy schemes for potential projects are proposed. The paper provides an idea of the geothermal well construction technologies, which can ensure the implementation of advanced geo-energy schemes. The problems of geothermal engineering and possible solutions to overcome them, which will contribute to the development of geothermal energy, as the most effective option for decarbonization, are indicated.

scholarly journals Engineered Fiber Based Lost Circulation Pill to Abridge Lost Circulation of Geothermal Well

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Apriyansah Toni ◽  
Astra Agus Pramana ◽  
Bambang Kustono
Keyword(s):  
Base Fluid ◽  
Trial And Error ◽  
Cement Slurry ◽  
Lost Circulation ◽  
Severe Loss ◽  
Geothermal Well ◽  
Flexible Fiber ◽  
Geothermal Wells ◽  
Surface Section ◽  
Cement Plug

<em>Loss circulation is a major problem and known as the biggest challenge during drilling and well construction.This can leadsto various consequences,such as stuck pipe, loss of material and time to combat the losses, and even losing the well itself. Severe loss circulation conditions are often met while drilling geothermal wells in Indonesia. Partial to total losses have start experienced since drilling the surface section. Cement plugs is one of the conventional methods to cure losses. Number of cement plugs differ from one well to another well. Even in some wells, number of cement plugs performed for loss circulation plug can be over 30 times with total of more than 4,000 barrels of cement slurry pumped. Solution other than basic loss circulation material and cement plug must be developed to optimize curing loss time. Engineered fiber base concentration which is include; Base Fluid, LCM and Solid Package was obtained from simulation, then trial and error in laboratory was conducted. Based on the final recipe, the control pill was able to hold pressure and not leaking, even when using 5 mm grid clearance. Additional combined stiff fiber and flexible fiber with concentration of 6 lbs/bbl sufficient to hold exessive loss circulation.</em>

scholarly journals Hacia la excelencia en la gerencia de proyectos a través del proceso de lecciones aprendidas -Towards excellence in project management through the lessons-learned process

2016 ◽  
Vol 3 (23) ◽  
pp. 82
Author(s):  
Clara Inés Díaz-Niño ◽  
Diana Milena Fraile-Neira ◽  
Diana Yesenia Rodríguez-Higuita ◽  
German Eduardo Giraldo-Gonzalez
Keyword(s):  
Project Management ◽  
Best Practices ◽  
Oil And Gas ◽  
Implementation Process ◽  
Lessons Learned ◽  
International Literature ◽  
Management Framework ◽  
Economic View ◽  
Modern Project ◽  
Buenas Prácticas

Este artículo describe y propone un proceso estándar de lecciones aprendidas dentro del marco de la gerencia moderna de proyectos, con base en la revisión de literatura nacional e internacional y el estado de implementación del proceso en 8 organizaciones pertenecientes al subsector de Hidrocarburos en Colombia. Este subsector, es uno de los más representativos, no sólo por lo económico, sino por ser un referente en la apropiación de las buenas prácticas de la gerencia moderna de proyectos. Como resultado del análisis cualitativo, realizado a través de entrevistas y encuestas, se propone el proceso, su caracterización, flujo de procedimiento e interacción de entradas, técnicas y salidas, para la identificación, documentación, análisis y aplicación de las lecciones aprendidas, que busca contribuir al crecimiento y competitividad del sector, y al mejoramiento de la efectividad de los procesos utilizando el aprendizaje basado en experiencias.Towards excellence in project management through the lessons-learned processABSTRACTThis paper describes and proposes a standard lessons-learned process within the framework of modern project management. The research is based on national and international literature review and the investigation of the implementation process status in Colombian oil and gas subsector. This subsector is one of the most important country subsectors, not only from the economic view but also for being one of the leaders in project management best practices appropriation. As a result of the qualitative analysis, documented through interviews and surveys, a process description, process flow and diagram interaction inputs, techniques and outputs is proposed, for the identification, documentation, analysis and application of lessons learned, looking for a standardized guide to run this process within the modern project management framework. This approach aims to contribute to sector growth and competitiveness, and process effectiveness improvement, using learning-based experiences.Para a excelência na gestão de projectos através do processo de lições aprendidasRESUMOEste artigo descreve e propõe um processo padrão de lições aprendidas no âmbito da moderna gestão de projetos, com base em uma revisão da literatura nacional e internacional e da situação da execução do processo em 8 organizações dentro do setor de hidrocarbonetos na Colômbia. Está sub-sector é um dos mais representativos, não só economicamente, mas como um líder na titularidade das boas práticas de gerenciamento de projeto moderno. Como resultado da análise qualitativa, realizada através de entrevistas e pesquisas, processamento, caracterização, fluxo de processo e interação de entradas, saídas e as técnicas de identificação, documentação, análise e aplicação das lições aprendidas é proposto, que visa contribuir para o crescimento e competitividade do sector e melhorar a eficácia dos processos, utilizando as experiências de aprendizagem baseado.

Successful Application of a Reinforced Composite Mat Pill Technology for Lost Circulation Control in the Norwegian Continental Shelf

2021 ◽  
Author(s):  
Jose A. Barreiro ◽  
John S. Knowles ◽  
Carl R. Johnson ◽  
Iain D. Gordon ◽  
Lene K. Gjerde
Keyword(s):  
Continental Shelf ◽  
Flow Rate ◽  
Drilling Fluid ◽  
Significant Loss ◽  
Lessons Learned ◽  
Cement Slurry ◽  
Lost Circulation ◽  
Reinforced Composite ◽  
Zonal Isolation ◽  
Norwegian Continental Shelf

Abstract An operator in the Norwegian continental shelf (NCS) required sufficient zonal isolation around a casing shoe to accommodate subsequent targeted injection operations. Located in the Ivar Aasen field, and classified as critical, the well had a 9 ⅝-in. casing shoe set in the depleted Skagerrak 2 reservoir. The lost circulation risk was high during cementing because the Hugin formation, located above the reservoir, contained 40 m [~ 131.2 ft] of highly porous and permeable sandstone. During previous operations in the field, lost circulation was observed before and during the casing running and cementing operations. After unsuccessful attempts to cure the losses with various lost circulation materials, a new solution was proposed to target the specific lost circulation problem by combining two types of reinforced composite mat pill (RCMP) technology. Specifically, the first type of RCMP technology was engineered for use in the viscous preflush spacer, and the second was applied to the cement slurry itself. Working in synergy, the RCMP systems mitigated the risk of incomplete zonal isolation. With no losses observed upon reaching total depth (TD) for the 12 ¼-in. hole, the 9 ⅝-in. casing was run with a reamer shoe and 15 rigid centralizers. Between 2700 and 2728 m [~ 8,858 and 8,950 ft] measured depth (MD), the rig observed constant drag of 30 to 40 MT whilst working the casing down, and circulation was completely lost before partial returns were eventually observed. The rig continued to work the string down to the planned landing depth at 3897 m [~ 12,785 ft] MD. Precementing circulation ensued with staged pump rates increasing at 100-L/min [~ 0.6-bbl/min] intervals up to 1400 L/min [~ 8.8 bbl/min], which induced losses at a rate of 6.5 m3/hour [~ 40 bbl/hour]). Subsequently, the flow rate was reduced to 1300 L/min [~ 8.1 bbl/min], and the annular volume was circulated 2.6 times with full returns. Attempts to reduce equivalent circulating density (ECD) ahead of the cementing operation were implemented at 1300 L/min [~ 8.1 bbl/min] using a low-density, low-rheology oil-based drilling fluid pill. However, a significant loss rate of 18.0 m3/hour [~113 bbl/hour] was observed. The flow rate was reduced to 950 L/min [~ 6.0 bbl/min], and partial circulation was recovered. After the spacer and cement had reached the annulus, full returns were immediately observed and continued until the top plug was successfully bumped. Acoustic logging determined that the operation had achieved the primary job objective of establishing the required length of hydraulically isolating cement in the annulus. Lost circulation is a costly problem that can be difficult to solve, even with the wide variety of technologies available (Vidick, B., Yearwood, J. A., and Perthuis, H. 1988. How To Solve Lost Circulation Problems. SPE-17811-MS). This case study demonstrates a successful solution. The operator will be able to incorporate lessons learned and best practices into future operations, and these lessons and practices will be useful to other operators with similar circumstances.

Delivering Zonal Isolation between Reservoir Sublayers in Long, Horizontal 12 ¼-in. Hole Sections in Extended Reach Wells

2021 ◽  
Author(s):  
Azza Elhassan ◽  
Ahmedagha Eldaniz Hamidzada ◽  
Toki Takahiro ◽  
Toma Motohiro ◽  
Mohd Waheed Orfali ◽  
...  
Keyword(s):  
High Pressures ◽  
Lessons Learned ◽  
Measurement Tool ◽  
Persistent Problem ◽  
Lost Circulation ◽  
Well Integrity ◽  
Starting Point ◽  
Discharge Policy ◽  
Zonal Isolation ◽  
Fluid Design

Abstract Good cementing practices are required to achieve effective zonal isolation and provide long-term well integrity for uninterrupted safe production and subsequent abandonment. Zonal isolation can be attained by paying close attention to optimizing the drilling parameters, hole cleaning, fluid design, cement placement, and monitoring. In challenging extended reach wells in the UAE, different methods were employed to deliver progressive improvement in zonal isolation. Cementing the intermediate and production sections in the UAE field is challenging because of the highly deviated, long, open holes; use of nonaqueous fluids (NAFs); and the persistent problem of lost circulation. Compounding the problem are the multiple potential reservoirs; the pressure testing of the casing at high pressures after cement is set; and the change in downhole pressures and temperatures during production phases, which results in additional stresses. Hence, the mechanical properties for cement systems must be customized to withstand the downhole stresses. The requirement of spacer fluids with nonaqueous compatible properties adds complexity. Lessons learned from prior operations were applied sequentially to produce fit-for-purpose solutions in the UAE field. Standard cement practices were taken as a starting point, and subsequent changes were introduced to overcome specific challenges. These challenges included deeper 12 ¼-in. sections, which made it difficult to manage equivalent circulating densities (ECDs), and a stricter requirement of zonal isolation across sublayers in addition to required top of cement at surface. To satisfy these requirements, several measures were taken gradually: applying engineered trimodal blend systems to remain under ECD limits; pumping a lower-viscosity fluid ahead of the spacer; using NAF-compatible spacers for effective mud removal; employing flexible cement systems to withstand downhole stresses; and modeling the cement job with an advanced cement placement software to simulate displacement rates, bottomhole circulating temperatures, centralizer placement, mud removal and comply with a zero discharge policy that restricts the extra slurry volume to reach surface. To enhance conventional chemistry-based mud cleaning, an engineered scrubbing additive was included in the spacers with a microemulsion-based surfactant. The results of cement jobs were analyzed by playback in advanced evaluation software to verify the efficiency of the applied solutions. This continuous improvement response to changes in well design has resulted in a significant positive change in cement bond logs; a flexural attenuation measurement tool has been used to evaluate the lightweight slurry quality behind the casing, which has helped in enhancing the confidence level in well integrity in these challenging wells. The results highlight the benefit of developing engineering solutions that can be adapted to respond to radical changes in conditions or requirements.

Overcoming Lost Circulation Risks in Low Fracture Gradient Formations with a New Tailored Spacer System

2021 ◽  
Author(s):  
Kory Hugentobler ◽  
Joseph M. Shine ◽  
Alejandro De La Cruz Sasso ◽  
Abdulmalek Shamsan ◽  
Sandip Patil ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Performance Testing ◽  
Lost Circulation ◽  
Oil And Gas Operations ◽  
Primary Cementing ◽  
Isolation Requirements ◽  
And Performance ◽  
Wellbore Strengthening ◽  
Placement Success ◽  
Fracture Gradient

Abstract In certain regions of oil and gas operations, lost circulation is a common occurrence, especially when a majority of the openhole exposed during primary cementing is carbonate-based formations. This can lead to lost circulation risks in most applications. To overcome lost circulation risks during primary cementing, a new tailored spacer system shows to improve the cement placement success. The manuscript discusses the quality assurance and performance testing with field cases demonstrating the value contributions of the spacer for achieving zonal isolation requirements as well as the top of cement objectives. The work efforts presented shows a spacer meeting and sometimes showing incremental wellbore strengthening in comparison to the published literature for existing available spacers used to overcome similar lost circulation risks.

scholarly journals Exploring in Asia, Africa and the Americas for oil & gas in naturally fractured basement reservoirs: best practices & lessons learned

Georesursy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 10-18 ◽  
Author(s):  
Tako Koning
Keyword(s):  
Best Practices ◽  
Oil And Gas ◽  
Lessons Learned ◽  
Reservoir Rock ◽  
Gas Reservoirs ◽  
Rock Types ◽  
Oil And Gas Fields ◽  
Basement Rocks ◽  
Basement Reservoirs ◽  
Gas Fields

Basement rocks are important oil and gas reservoirs in a number of basins in the world. The basement oil and gas play has intensified in the past decade with significant basement discoveries. This paper provides a technical review of select basement oil and gas fields in Asia, Africa and the Americas. “Best practices” for exploring and developing basement fields are reviewed. Failures are also considered since basement reservoirs can be very complicated and unpredictable. Preference scale for basement reservoir rock types is presented. The opinion of this author is that the best rock types are fractured quartzites or granites since they are brittle and thus fracture optimally. Based on international experience, recommendations on the study of crystalline basement for oil and gas and the development of deposits in it are given.

Technology Focus: Sand Management (October 2021)

2021 ◽  
Vol 73 (10) ◽  
pp. 67-67
Author(s):  
Imran Abbasy
Keyword(s):  
Oil And Gas ◽  
International Energy Agency ◽  
Lessons Learned ◽  
Energy Agency ◽  
Net Zero ◽  
Successful Case ◽  
Sand Control ◽  
Zonal Isolation ◽  
The University ◽  
Gravel Pack

Our industry is under pressure to produce cleaner energy. That is the mantra, more so than a few years ago. A recent report from the International Energy Agency suggested that all greenfield developments in the oil and gas sector should be stopped forthwith if we are to achieve the net-zero target by 2050. That essentially means that we squeeze what we can from the not-so-easy and mature reservoirs, many of which have sand-control problems. Perhaps that is the reason most operators are working ever harder to manage and produce such assets, a trend reflected in the number of papers written. More importantly, a large proportion of papers this year were on sand consolidation and through-tubing exclusion methods, which primarily target mature producing reservoirs. A few technology trends are becoming apparent. There is a move to gravel pack longer and longer horizontal sections. It is now possible to pack more than 7,000 ft with zonal isolation. Through-tubing sand-control remediation continues to evolve. Sand consolidation is moving toward nanoparticles, with a promise of better regained permeability. Further strides have been made in developing filters to achieve behind-screen compliance for better sand retention. Industry has been enchanted by what data analytics and machine learning can potentially offer, and perhaps rightly so. Several papers this year apply these tools to sand management. For those interested, I would recommend paper SPE 200949 and OTC 31234 as further reading. Unfortunately, from a sand-control perspective, I do not yet see a compelling narrative. One interesting statistic that I stole from a LinkedIn post is that the rising 3-year trend of papers in OnePetro on this subject has fallen dramatically between 2020 and 2021. I have not independently verified these figures, but it does tell a story. Is the excitement waning? Recommended additional reading at OnePetro: www.onepetro.org. SPE 203238 - Sanding Propensity Prediction Technology and Methodology Comparison by Surej Kumar Subbiah, Universiti Teknologi Malaysia and Schlumberger, et al. SPE 201768 - Using Artificial Intelligence for Determining Threshold Sand Rates From Acoustic Monitors by Srinivas Swaroop Kolla, The University of Tulsa, et al. OTC 30386 - Pioneering Slickline Deployed Through Tubing Gravel Pack in Malaysia: Successful Case Study and Lessons Learned by Ertiawati Mappanyompa, Petronas, et al.

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