Thickness Optimization of Drilling Fluid Filter Cakes for Cement Slurry Filtrate Control and Long-Term Zonal Isolation

1995 ◽  
Author(s):  
James E. Griffith ◽  
Samuel Osisanya
Keyword(s):  
Drilling Fluid ◽  
Thickness Optimization ◽  
Cement Slurry ◽  
Fluid Filter ◽  
Zonal Isolation ◽  
Filter Cakes

The Research and Application of Cementing Isolation Technology in High Porosity and Permeability of Developed Clastic Rock Reservoir in Tarim Basin

2021 ◽  
Author(s):  
Hongtao Liu ◽  
Zhengqing Ai ◽  
Jingcheng Zhang ◽  
Zhongtao Yuan ◽  
Jianguo Zeng ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Water Layer ◽  
High Porosity ◽  
Self Healing ◽  
Cement Slurry ◽  
Clastic Rock ◽  
Pump Rate ◽  
Porosity And Permeability ◽  
Zonal Isolation ◽  
High Pump

Abstract The average porosity and permeability in the developed clastic rock reservoir in Tarim oilfield in China is 22.16% and 689.85×10-3 μm2. The isolation layer thickness between water layer and oil layer is less than 2 meters. The pressure of oil layer is 0.99 g/cm3, and the pressure of bottom water layer is 1.22 g/cm3, the pressure difference between them is as bigger as 12 to 23 MPa. It is difficult to achieve the layer isolation between the water layer and oil layer. To solve the zonal isolation difficulty and reduce permeable loss risk in clastic reservoir with high porosity and permeability, matrix anti-invasion additive, self-innovate plugging ability material of slurry, self-healing slurry, open-hole packer outside the casing, design and control technology of cement slurry performance, optimizing casing centralizer location technology and displacement with high pump rate has been developed and successfully applied. The results show that: First, the additive with physical and chemical crosslinking structure matrix anti-invasion is developed. The additive has the characteristics of anti-dilution, low thixotropy, low water loss and short transition, and can seal the water layer quickly. Second, the plugging material in the slurry has a better plugging performance and could reduce the permeability of artificial core by 70-80% in the testing evaluation. Third, the self-healing cement slurry system can quickly seal the fracture and prevent the fluid from flowing, and can ensuring the long-term effective sealing of the reservoir. Fourth, By strict control of the thickening time (operation time) and consistency (20-25 Bc), the cement slurry can realize zonal isolation quickly, which has achieved the purpose of quickly sealing off the water layer and reduced the risk of permeable loss. And the casing centralizers are used to ensure that the standoff ratio of oil and water layer is above 67%. The displacement with high pump rate (2 m3/min, to ensure the annular return velocity more than 1.2 m/s) can efficiently clean the wellbore by diluting the drilling fluid and washing the mud cake, and can improve the displacement efficiency. The cementing technology has been successfully applied in 100 wells in Tarim Oilfield. The qualification rate and high quality rate is 87.9% and 69% in 2019, and achieve zone isolation. No water has been produced after the oil testing and the water content has decreased to 7% after production. With the cementing technology, we have improved zonal isolation, increased the crude oil production and increased the benefit of oil.

Nanosized Magnesium Oxide With Engineered Expansive Property for Enhanced Cement-System Performance

SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1681-1689 ◽  
Author(s):  
Narjes Jafariesfad ◽  
Mette Rica Geiker ◽  
Pål Skalle
Keyword(s):  
Heat Treatment ◽  
Young’S Modulus ◽  
Magnesium Oxide ◽  
Young's Modulus ◽  
Oil Well ◽  
Cement Slurry ◽  
Expansive Agent ◽  
Cement System ◽  
Zonal Isolation

Summary The bulk shrinkage of cement sheaths in oil wells can result in loss of long-term zonal isolation. Expansive additives are used to mitigate bulk shrinkage. To compensate effectively for bulk shrinkage during the late plastic phase and the hardening phase of the cement system, the performance of the expansive additive needs to be regulated considering the actual cement system and placement conditions. This paper presents an introductory investigation on the potential engineering of nanosized magnesium oxide (MgO) (NM) through heat treatment for use as an expansive agent in oilwell-cement systems. In this study, the bulk shrinkage of a cement system was mitigated by introducing NM with designed reactivity to the fresh cement slurry. The reactivity of NM was controlled by heat treatment. A dilatometer with corrugated molds was used to measure the linear strain of samples cured at 40°C and atmospheric pressure. The effect of NMs differing in reactivity on tensile properties of cement systems cured for 3 days at 40°C was examined by use of the flattened Brazilian test. The reactivity of the NM played a key role in controlling the bulk shrinkage of the cement system. Addition of only 2% NM by weight of cement (BWOC) with appropriate reactivity was sufficient to maintain expansion of the cement system. Adding NM to the cement system also resulted in improved mechanical flexibility. The NM with highest reactivity caused the largest reduction in Young's modulus at 3 days and, in general, the ratio of tensile strength to Young's modulus improved through the addition of NM to the cement system. Our work demonstrates that controlling the reactivity of the additive is a promising method to mitigate bulk shrinkage of cement systems and thereby to sustain the mechanical properties of the cement sheath in the oil well at an acceptable level.

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.

scholarly journals The influence of low amounts on in situ-polymerized bisphenol-diamine net in cement slurries prepared in seawater – structural analysis after long-term contact with in situ-generated mud-acid fracturing fluid

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Danilo Oliveira Santos ◽  
Ivory Marcos Gomes dos Santos ◽  
Joenesson Filip Santos Ribeiro ◽  
Eunice Fragoso Silva Vieira ◽  
Gwenn Le Saoût ◽  
...  
Keyword(s):  
Oil Well ◽  
Cement Slurry ◽  
27Al Nmr ◽  
Chemical Structures ◽  
Zonal Isolation ◽  
Order Variable ◽  
Adsorption Desorption ◽  
Kinetic Features

ABSTRACT Inadequate zonal isolation in oil wells can provoke safety and environmental problems. New cement slurries can avoid such problems. In this work, novel cement slurries were prepared in the presence of seawater with in situ-formed epoxy resin–ethylenediamine. The new slurries were tested in relation to their mechanical properties and characterized by FTIR, XRD, TG/DTG, porosimetry by N2 adsorption-desorption and solid-state 29Si and 27Al NMR. Some kinetic features of long-term contact of the slurries with in situ-generated mud-acid were performed to evaluate the performances of the new slurries in routine acidizing procedures in oil well industry. The experimental kinetic data were well fitted to order-variable exponential kinetic model and a factorial design of four variables (24). In these studies, it was possible to evaluate in detail how some important experimental factors act on the quantities of acid that interact with the pastes, as well as to verify how these factors affect the speed with which the mud-acid interacts with the slurries. The results strongly suggest that the interactions occurred at epoxy/ethylenediamine cement slurry/mud-acid interfaces are due to surface reactions with preservation of the chemical structures of the cement slurries, even after long-term contact with mud-acid. The new cement slurry present good features to be used in environmental-friendly procedures in oil well field.

Wellbore Stabilizing Technology Enhances Cementing Efforts in the North Sea

2021 ◽  
Author(s):  
Agnieszka Ilnicka ◽  
Antonio Bottiglieri ◽  
Maja Jaskiewicz ◽  
David Kulakofsky
Keyword(s):  
North Sea ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Weak Zone ◽  
Two Fluids ◽  
The North ◽  
Zonal Isolation ◽  
The North Sea ◽  
Isolation Requirements ◽  
Cement Integrity

Abstract North Sea lithologies are often complex creating a difficult environment to deliver effective zonal isolation with standard cementing practices. With ever-present weak, fractured, and unconsolidated formations, the practice of fully lifting heavier cement up the annular gap between the formation and the casing or liner often times compromises the formation and the cement integrity. Wellbore Stabilizing (WBS) technology has been shown capable of providing zonal isolation under these difficult conditions. A cementing spacer has been developed that incorporates WBS technology providing a simple way to deliver the technology in front of any cement job, without compromising the cement integrity or requiring any last-minute slurry design or redesign. By separating the placement of the WBS technology from the cement itself, the cement slurry can be designed with the sole focus being on the interval's zonal isolation requirements. On Askepott wells in the Norwegian part of the North Sea, the Nordland weak zone is encountered after drilling out the 30-inch shoe from the Oseberg Vest H template. Cement back to the seafloor is required when cementing the 20-in casing in these 26-in. holes. Prior to the introduction of the WBS technology, pressure had been observed on the D-annulus, hinting at a lack of sufficient cement circulation. With assistance from this new WBS spacer, pressure is no longer observed in the D-annulus indicating the cement is now being circulated back inside of the conductor string. The WBS spacer has also been used successfully ahead of cement across the production interval in wells where losses were typically expected, and again full returns were observed. Normally cement spacers are utilized to separate the drilling fluid from the cement as these two fluids are normally incompatible with each other and to help push the drilling fluid out of the well so the annulus may be completely filled with cement. If the drilling fluid is not successfully displaced from the annular space, the zonal isolation intended by the primary cement job is usually less than ideal. In addition to these standard functions in preparation for cementing operations, this specialized WBS spacer also can prevent loss of cement to the formation.

Application of Key Technique in Splitter Wellhead Cementing Enabled Successful and Safe Operations

2021 ◽  
Author(s):  
Chee Hen Lau ◽  
Avinash Kishore Kumar ◽  
Myat Thuzar
Keyword(s):  
Cost Savings ◽  
Pressure Profile ◽  
Construction Technology ◽  
Cementing Technique ◽  
Cement Slurry ◽  
Planning Phase ◽  
Well Design ◽  
Zonal Isolation ◽  
Unique Approach

Abstract This paper describes the application of key technique for splitter wellhead cementing of top-hole section in conductor-sharing wells in dozens of development wells in offshore Malaysia. Its objective is to elaborate on the challenges faced during the well planning phase, methodology of cementing technique, cementing slurry design as well as solutions outcome and lessons learnt. Limitations of current software in the industry to simulate the conductor-sharing well cementation and approaches to maneuver through these limitations are also discussed. During the well planning phase, cementing technique to address the risks associated with splitter wellhead cementing such as accidental cementation of dummy string, poor cement coverage in shared conductor, and losses uncertainties were analyzed. The cementing execution results of first batch of wells are examined, i.e. pressure profile, cement returns as well as opportunities for improvement were documented and translated into recommendations leading to eventual success for future well design. The cement slurry design for each casing in the splitter wellhead are also established based on its associated job objectives which is based on the unique approach in splitter wellhead cementing. The establishment of key cementing technique for such an unconventional well construction technology is important in order to ensure continuous success both in cement placement as well as cement slurry design. The best practices are currently being replicated by other major operators in Malaysia for all splitter wellhead cement design. The learnings from the technique are incorporated into the technical standard of Malaysia operator as well to serve as a specific mandated requirement for future operations. An integrated study of wellhead design, drilling practices and cementing technologies enabled a novel methodology to assure long term zonal isolation for the wells and innovation in the cementing approach enable cost savings for the operator as the wells can be drilled in a safe, efficient and cheaper way.

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.

A Novel Approach to Successfully Cement the Long Horizontal Liners Across Khuff-C Reservoir in High-Pressure Gas Producer Land Wells: A Case History from Saudi Arabia

2021 ◽  
Author(s):  
Wajid Ali ◽  
Freddy Jose Mata ◽  
Faisal Abdullah Al-Turki
Keyword(s):  
Drilling Fluid ◽  
Horizontal Wells ◽  
Gas Migration ◽  
Cement Slurry ◽  
Oil Companies ◽  
Temperature Modeling ◽  
Novel Approach ◽  
Open Hole ◽  
Zonal Isolation ◽  
Testing Field

Abstract Maintaining zonal isolation is vital to well economics and productive life. Well integrity is becoming more challenging with the drilling of deeper, highly deviated, and horizontal wells worldwide. Oil companies are focused on to enhance the well productivity during drilling long horizontal wells in a harsh environment by achieving maximum accessible reservoir contact. These wellbore geometries incorporate additional challenges to design and deliver a dependable barrier. In this paper, a case study about cementing the longest liner across Khuff-C reservoir has been presented discussing the main challenges, engineering considerations, field implementation, results, and conclusions. The well was drilled horizontally across Khuff-C carbonates using oil-based drilling fluid. The 5-7/8-in open hole section was planned to be cemented in single stage, utilizing 8370 ft of a 4-1/2-in liner. Careful attention was paid to estimate the bottom hole circulating temperature, using the temperature modeling simulator. A 118-lbm/ft3 slurry was designed to keep the equivalent circulation density intact. Gas migration control additives were included in the slurry design to lower the slurry's transition time, in order to reduce the chances of gas migration through the cement slurry. The slurry was batch-mixed to ensure the homogeneity of the final slurry mixture. A reactive spacer was designed to improve the cement bonding from long term zonal isolation perspective. Additionally, the spacer was loaded with optimum amounts of surfactant package to serve as an aid to remove the mud and to water-wet the formation and pipe for better cement bonding. Centralizers placement plan was optimized to allow around 63% average standoff around the pipe, staying within the torque and drag (T&D) limits. The cement treatment was performed as designed and met all zonal isolation objectives. The process of cementing horizontal liners comes with unique procedures. There are several challenges associated with carrying out wellbore zonal isolation for primary cementing of horizontal liners, therefore, a unique level of attention is required during the design and execution stages. The slurry design requires careful formulation to achieve the desired specifications while ensuring its easy deployment and placement in the liner annulus. By planning in advance and following proven techniques, many of the problems associated with the running and cementing of deep and long horizontal liners can be alleviated. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technique can be a key resource for such operations in the future. The paper describes the process used to design the liner cement job and how its application was significant to the success of the job.

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