Improving Cement-to-Pipe Bonding Evaluation on Coated Casing

2021 ◽  
Author(s):  
Barry Albert Lumankun ◽  
Diyah Ayu Adiningtyas ◽  
Cinto Azwar ◽  
Ahmed Osman ◽  
Rudi Hartanto ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Weight Ratio ◽  
Fundamental Aspect ◽  
Evaluation Tool ◽  
Bond Quality ◽  
Cement Slurry ◽  
Well Integrity ◽  
Zonal Isolation ◽  
Bond Evaluation ◽  
Construction Operation

ABSTRACT In the Oil and Gas industries, drilling a well in both exploration and development operations is becoming more challenging due to the reservoir location and complex reservoir system. A sophisticated high-cost well structure with complex trajectory, subsea system, or even operating in deep water is sometimes unavoidable. One of the crucial factors for a successful well construction operation is to achieve excellent well integrity by having good zonal isolation throughout the target reservoir section. This requires flawless primary cementation from cement job planning, design, and up to execution. The cement bond quality will need to be evaluated by performing the post job cement execution evaluation and wireline logging cement bond log survey. Supported with more stringent regulations, well integrity is becoming a fundamental aspect in drilling and production operations. This brings new challenges to cementing operations and subsequent cement evaluation. Flawless primary cementation is of great importance, from the job planning, design, to the execution. Post-job cement evaluations are needed by performing Pressure Match Post-Job Analysis and Wireline Logging Cement Bond Log Survey. Key parameters in designing optimum zonal isolation cement slurry is good understanding of the wellbore technical challenges and mitigating all geological and formation-related risks, such as narrow pressure margin, gas migration risk, etc. Light cement, complicated cement composition recipes, small cement - mud weight ratio are more common these days, supported with the developing technology in cementing. These, on the other side, would impact the cement bond evaluation. Good cement bond is crucial to ensure good zonal isolation across the reservoir intervals. Casing external coating, applied to protect casing strings from rusts, is another aspect affecting the cement bond, especially cement-to-casing bond. A more advanced cement bond evaluation tool will be required to cope with variety of cementing conditions, to enable producing undoubted log results. Thus, helping Operator in making decisions of subsequent well operations. This paper shows and presents different cement bond log interpretation results from four wells executed with a different method of implementations, performed in a development drilling campaign in Natuna Sea, offshore Indonesia in year 2019. The paper will focus on the 9-5/8" casing cementation, on which the cement bond evaluation became one of the main attentions.

Implementation of Factory Cementing Concept in the High-Intensity Drilling Environment of Khazzan, Sultanate of Oman

2021 ◽  
Author(s):  
Emmanuel Therond ◽  
Yaseen Najwani ◽  
Mohamed Al Alawi ◽  
Muneer Hamood Al Noumani ◽  
Yaqdhan Khalfan Al Rawahi ◽  
...  
Keyword(s):  
Shallow Water ◽  
High Intensity ◽  
Sultanate Of Oman ◽  
Cement Slurry ◽  
Short Term ◽  
Lost Circulation ◽  
Well Integrity ◽  
Sustained Casing Pressure ◽  
Zonal Isolation ◽  
Casing Pressure

Abstract The Khazzan and Ghazeer gas fields in the Sultanate of Oman are projected to deliver production of gas and condensate for decades to come. Over the life of the project, around 300 wells will be drilled, with a target drilling and completion time of 42 days for a vertical well. The high intensity of the well construction requires a standardized and robust approach for well cementing to deliver high-quality well integrity and zonal isolation. The wells are designed with a surface casing, an intermediate casing, a production casing or production liner, and a cemented completion. Most sections are challenging in terms of zonal isolation. The surface casing is set across a shallow-water carbonate formation, prone to lost circulation and shallow water flow. The production casing or production liner is set across fractured limestones and gas-bearing zones that can cause A- and B-Annulus sustained casing pressure if not properly isolated. The cemented completion is set across a high-temperature sandstone reservoir with depletion and the cement sheath is subjected to very high pressure and temperature variations during the fracturing treatment. A standardized cement blend is implemented for the entire field from the top section down to the reservoir. This blend works over a wide slurry density and temperature range, has expanding properties, and can sustain the high temperature of the reservoir section. For all wells, the shallow-water flow zone on the surface casing is isolated by a conventional 11.9 ppg lightweight lead slurry, capped with a reactive sodium silicate gel, and a 15.8 ppg cement slurry pumped through a system of one-inch flexible pipes inserted in the casing/conductor annulus. The long intermediate casing is cemented in one stage using a conventional lightweight slurry containing a high-performance lost circulation material to seal the carbonate microfractures. The excess cement volume is based on loss volume calculated from a lift pressure analysis. The cemented completion uses a conventional 13.7 - 14.5 ppg cement slurry; the cement is pre-stressed in situ with an expanding agent to prevent cement failure when fracturing the tight sandstone reservoir with high-pressure treatment. Zonal isolation success in a high-intensity drilling environment is assessed through key performance zonal isolation indicators. Short-term zonal isolation indicators are systematically used to evaluate cement barrier placement before proceeding with installing the next casing string. Long-term zonal isolation indicators are used to evaluate well integrity over the life of the field. A-Annulus and B-Annulus well pressures are monitored through a network of sensors transmitting data in real time. Since the standardization of cementing practices in the Khazzan field short-term job objectives met have increased from 76% to 92 % and the wells with sustained casing pressure have decreased from 22 % to 0%.

Enhanced Cement Composition for Preventing Annular Gas Migration

2019 ◽  
Author(s):  
George Kwatia ◽  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Oil Well ◽  
Gas Migration ◽  
Cement Slurry ◽  
Gas Industry ◽  
Well Integrity ◽  
Transit Times ◽  
Well Cement ◽  
Gas Tight

Abstract Cementing operations in deepwater exhibit many challenges worldwide due to shallow flows. Cement sheath integrity and durability play key roles in the oil and gas industry, particularly during drilling and completion stages. Cement sealability serves in maintaining the well integrity by preventing fluid migration to surface and adjacent formations. Failure of cement to seal the annulus can lead to serious dilemmas that may result in loss of well integrity. Gas migration through cemented annulus has been a major issue in the oil and gas industry for decades. Anti-gas migration additives are usually mixed with the cement slurry to combat and prevent gas migration. In fact, these additives enhance and improve the cement sealability, bonding, and serve in preventing microannuli evolution. Cement sealability can be assessed and evaluated by their ability to seal and prevent any leakage through and around the cemented annulus. Few laboratory studies have been conducted to evaluate the sealability of oil well cement. In this study, a setup was built to simulate the gas migration through and around the cement. A series of experiments were conducted on these setups to examine the cement sealability of neat Class H cement and also to evaluate the effect of anti-gas migration additives on the cement sealability. Different additives were used in this setup such as microsilica, fly ash, nanomaterials and latex. Experiments conducted in this work revealed that the cement (without anti-gas migration additive) lack the ability to seal the annulus. Cement slurries prepared with latex improved the cement sealability and mitigated gas migration for a longer time compared to the other slurries. The cement slurry formulated with a commercial additive completely prevented gas migration and proved to be a gas tight. Also, it was found that slurries with short gas transit times have a decent potential to mitigate gas migration, and this depends on the additives used to prepare the cement slurry.

Application of Resin-Cement Blend to Prevent Pressure Build-Up in Casing to Casing Annulus CCA: A Novel Approach to Improve Well Integrity

2021 ◽  
Author(s):  
Wajid Ali ◽  
Freddy Jose Mata ◽  
Ahmed Atef Hashmi ◽  
Abdullah Saleh Al-Yami
Keyword(s):  
High Pressure ◽  
Shear Bond Strength ◽  
Resin Cement ◽  
Cement Slurry ◽  
Well Integrity ◽  
Cement System ◽  
Zonal Isolation ◽  
Primary Cementing ◽  
Cement Sheath

Abstract Assurance of well integrity is critical and important throughout the entire well's life cycle. Pressure build-up between cemented casings annuli has been a major challenge all around the world. Cement is the main element that provides isolation and protection for the well. The cause for pressure build-up in most cases is a compromise of cement sheath integrity that allows fluids to migrate through micro-channels from the formation all the way to the surface. These problems prompt cementing technologists to explore new cementing solutions, to achieve reliable long-term zonal isolation in these extreme conditions by elevating shear bond strength along-with minimal shrinkage. The resin-cement system can be regarded as a novel technology to assure long term zonal isolation. This paper presents case histories to support the efficiency and reliability of the resin-cement system to avoid casing to casing annulus (CCA) pressure build-up. This paper presents lab testing and application of the resin-cement system, where potential high-pressure influx was expected across a water-bearing formation. The resin-cement system was designed to be placed as a tail slurry to provide a better set of mechanical properties in comparison to a conventional slurry. The combined mixture of resin and cement slurry provided all the necessary properties of the desired product. The slurry was batch-mixed to ensure the homogeneity of resin-cement slurry mixture. The cement treatment was performed as designed and met all zonal isolation objectives. Resin-cement’s increased compressive strength, ductility, and enhanced shear bond strength helped to provide a dependable barrier that would help prevent future sustained casing pressure (SCP). The producing performance of a well depends in great part on a good primary cementing job. The success of achieving zonal isolation, which is the main objective of cementing, is mainly attributed to the cement design. The resin-cement system is evolving as a new solution within the industry, replacing conventional cement in many crucial primary cementing applications. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technology can be a key resource for such operations in the future. The paper describes the process used to design the resin-cement system and how its application was significant to the success of the jobs. By keeping adequate strength and flexibility, this new cement system mitigates the risk of cement sheath failure throughout the life of well. It provides a long-term well integrity solution for any well exposed to a high-pressure environment.

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.

Experimental and CFD Study of Circulation Efficiency in Simulated Irregular Annulus

2018 ◽  
Author(s):  
Shreyansh Divyankar ◽  
Milad Khatibi ◽  
Rune Wiggo Time ◽  
Hans Joakim Skadsem ◽  
Jan Aage Aasen
Keyword(s):  
Vector Fields ◽  
Liquid Velocity ◽  
Velocity Profiles ◽  
Oil Well ◽  
Cement Slurry ◽  
Rectangular Slot ◽  
Zonal Isolation ◽  
Irregular Geometry ◽  
Construction Operation ◽  
Narrow Annuli

Primary cementing is a critical well construction operation that should ensure annular zonal isolation over the life cycle of the oil well. Efficient conditioning and mobilisation of mud prior to cementing is important to ensure that residual mud, especially in washout zones, does not contaminate the cement slurry. Therefore, experiments are carried out to better understand the flow dynamics and associated phenomenon in irregular geometry. The narrow annulus between casing and formation is approximated by a rectangular slot, in order to aid instrumentation and data acquisition purposes. This methodology can be justified to reproduce flow in narrow annuli fairly well, and is considered a very useful technique for measurement in narrow geometries. Particle image velocimetry (PIV) is used to obtain the liquid velocity profiles in regular and irregular sections of the experimental setup. Analysis of velocity profiles and vector fields provides information on regions of flow in the vicinity of the irregularity, and this allows a systematic study on the effects of flow rate in regular and irregular wellbore geometries. Entry effects from regular to irregular section and the development of areas with recirculation zones are investigated in irregular section. This enables us to estimate variability of circulation efficiencies in the irregularity. The experimental results are compared with numerical simulations in corresponding irregular geometry.

Optimization of the Cement Slurry Compositions With Addition of Zeolite for Cementing Carbon Dioxide Injection Wells

2015 ◽  
Author(s):  
Krunoslav Sedić ◽  
Nediljka Gaurina-Medjimurec ◽  
Borivoje Pašić
Keyword(s):  
Carbon Dioxide ◽  
Oil And Gas ◽  
Co2 Injection ◽  
Carbon Dioxide Injection ◽  
Cement Slurry ◽  
Gas Reservoirs ◽  
Injection Wells ◽  
Standard Size ◽  
Well Integrity ◽  
Well Cement

Well integrity related to carbon dioxide injection into depleted oil and gas reservoirs can be compromised by corrosion which can affect casing, downhole and surface equipment and well cement. Impact on well cement can cause overall degradation of set cement and lead to migration of carbon dioxide back to the surface. Thus, special types of cements should be used. One of the acceptable solutions is application of cement blends based on a mixture of Portland cement and pozzolans. The present paper deals with optimization of the cement slurry design containing zeolite which is nowadays widely used due to its high pozzolan activity potential. Cement blends containing 20%, 30% and 40% zeolite clinoptilolite were used. Cement slurries were optimized for application in slim hole conditions on CO2 injection wells on Žutica and Ivanić oil fields in Croatia (Europe), where an old and deteriorated production casing was re-lined with new smaller sized one. Results obtained by this study suggest that cement slurry containing zeolite can be optimized for application in well conditions related to CO2 injection and underground storage, ranging from a slim hole to standard size casing cement jobs which leads to an improvement of well integrity related to CO2 injection.

Robust Leakage Modeling for Plug and Abandonment Applications

2019 ◽  
Author(s):  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
Differential Pressure ◽  
Cement Slurry ◽  
High Pressure And Temperature ◽  
Gas Leakage ◽  
Fluid Leakage ◽  
Well Integrity ◽  
Cement Plug

Abstract Oil and gas wells that require to be shut off forever, after depleting their reserves, need to be plugged and abandoned. Plug and Abandonment (P&A) operations induce many arduous challenges worldwide. The aim of P&A is to isolate and prevent fluid leakage in the wellbore in such a way that all fluids are contained in their formation for an undefined time. Failure of P&A in isolating and preventing fluid leakage can jeopardize the well integrity. Cement plugs that are used in this operation play a crucial role in maintaining the well integrity. Cement is considered as a porous medium that has an ultra-low permeability that can be achieved when some additives are used in the cement slurry to reduce its permeability and pore space. The cement plug may deteriorate with time under harsh downhole conditions, such as high pressure and temperature and exposure to different fluids. Cement plug deterioration will result in increasing the cement permeability or the overall permeability by creating channels or microannuli. In this study, several scenarios are presented for gas leakage through cement plugs. In these leakage scenarios, the differential pressure across the cement plug was varied. The aim of generating these scenarios is to investigate the current required cement plug length. In each scenario, four different permeability values were used to assess the risk associated with each value. In addition, the cement plug length was varied to investigate how the cement plug length is going to help ensure good well integrity. The leakage scenarios presented revealed that longer cement plugs have a longer leakage time. In addition, the results show an increase of leakage time as microannulus gap permeability decreases. Differential pressure exerted on the cement plug have a strong effect on the leakage time. To achieve a long term well integrity in P&A phase, an ultra-low permeable cement plug with excellent bonding, longer cement plug, and a lower differential pressure across the cement must be considered.

Smart Communicative Cement: On the Move Towards the Future of Zonal Isolation Monitoring

2018 ◽  
Author(s):  
Ricardo Cesar Bezerra de Melo ◽  
Ramy N. Eid
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Global Scale ◽  
Actual State ◽  
Bottom Line ◽  
Well Integrity ◽  
Technological Advances ◽  
The Future ◽  
Zonal Isolation ◽  
Dollar Amount

The oil and gas industry, by default, has been pretty conservative when it relates to innovation and drastic changes in mind-set. Mainly focused on the costly drilling and completion steps, some of the “smaller” services have been ignored. As such, Repsol has decided to take a deeper look at nano and micro sensored technologies in other industries and potentially replicate some of this innovation, allowing the industry to take “a step” closer to smarter zonal isolation. In general, the industry is quite aware of well integrity issues that we face. Be it immediate (whilst drilling/completing), within the life of production or even during the abandonment phase. There are many statistics proving that on a global scale, there are well integrity and sustained casing pressure issues on about 30–60% of all drilled wells. And we can confirm that a majority of these are directly related to well-cementing, creating an immense impact(s), that can negatively influence overall HSE, loss of potential reserves and bottom line dollar-amount. The ability to take a close look at well cementing has only proven feasible in a laboratory environment, beyond that, the knowledge and prediction of the actual state of the zonal isolation has proven difficult, confusing or costly. Regardless of the improved best practices, enhanced logging tools or state-of-the-art technological advances in chemicals/systems — we still seem to have that unanswered “gap” — on what actually happened, when it happened and how to avoid it in the future. This paper describes the background, the thought process and the potential advantage of ours proposed ideology, let Alone ongoing R&D efforts to improve the cement isolation quality, measurements and real time monitoring of its properties and integrity during the well life and after abandonment by sensoring it and communicating back to surface.

Novel Automated Light Foam Cementing Set-Up Brings Operational Efficiency to Major Operator in Norwegian North Sea Sector

2021 ◽  
Author(s):  
Ann-Marie Ekwue ◽  
Antonio Bottiglieri ◽  
Yasser Haddad ◽  
Agnieszka Walania ◽  
Toby Harkless ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Oil And Gas ◽  
Control Flow ◽  
Displacement Efficiency ◽  
Cement Slurry ◽  
Start Up ◽  
Zonal Isolation ◽  
Isolation Requirements ◽  
Critical Components ◽  
Set Up

Abstract As oil and gas operators are constantly looking for ways to increase efficiency in their operations, one area of well construction that is becoming increasingly popular is in the field of foam cementing. Foamed cement slurries are designed to have low density with relatively high compressive strength to enable operators accomplish their zonal isolation requirements. In addition, the enhanced slurry mobility of these energized fluids leads to a high displacement efficiency to ensure uniform cement coverage in the annulus. The use of foamed cement slurries particularly for top-hole sections in deep-water environments has increased over the past decade. For large volume jobs such as these, operators utilize the standard Automated Foam Cement System (AFCS) which comprises of high-pressure nitrogen pumps /converter and portable liquid nitrogen tanks. The AFCS automatically controls nitrogen and cement slurry based on the downhole rate and precisely maintains a desired foam cement density. For smaller volume jobs, the main constraint to deploying the standard AFCS is mainly rig deck space limitations, thus a "light foam package" was developed. The light package, fully developed in Norway, maintains the already well-established characteristics of automation from the standard AFCS; with the added benefit of minimizing footprint on board the rig with equipment which includes foam manifold, gas bottle rack and nitrogen control flow valve vs. the conventional liquid nitrogen tanks, pumps, and back up equipment. Other advantages of this set up include much faster rig up time due to smaller and lighter liftsimproved HSE benefits of eliminating liquid nitrogen handling; as well as limiting number of people required offshorefull job accuracy and automatic control with the utilization of mass flowmeters to measure nitrogen and cement rates with precisionrobust system with 100% redundancy of critical components This publication highlights the job details from a light foam job performed on a 30in conductor in a well on the Norwegian Continental Shelf, with the objective to cement the entire conductor length to seabed. This job was conducted in a field where numerous past cement jobs had failed to bring cement up to seabed and top up jobs with grout were the norm to achieve top of cement. With this simplified foam cementing process, the vision is that this kind of system set-up can make foam cementing a reality even in the most remote of locations and/or locations with small deck space, with reduced start-up costs.

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