Thermal well screen plugging: revisiting an old challenge (Part 1)

This paper presents results from novel tests investigating screen plugging and the factors that influence it. The study focuses on sand retention and flow convergence into screens, assuming formation collapse. Controlled experiments were conducted to evaluate the performance of different screens and the role of sand in plugging. The tests also explore how drilling and completion processes affect screen performance and plugging behavior. A novel test procedure was developed to simulate sand retention on screens. Screens with retained sand were placed in a flow apparatus to study multiphase flow behavior. A mix of sand and fines slurry was used to evaluate screen and near-screen plugging. The effect of mud and filter cake was assessed by allowing cake formation on the sand face before flowing. Additionally, the influence of temperature—up to 200°C—was examined to understand thermal impacts on screen plugging mechanisms under realistic downhole conditions. This study utilized three Particle Size Distribution (PSD) classes from the McMurray Formation to represent common variations in thermal project sands. A common polymeric mud, representative of the mud system used in thermal drilling, was employed.

The thickness of the mud cake varied significantly among the three sands and was directly related to their permeability, with finer sands forming denser cakes that reduced retained permeability by over 55% in the lowest permeability class. Experiments during the drawdown phase revealed that wire-wrapped screens outperformed punch screens in permeability recovery due to enhanced channeling, with coarser PSDs showing better restoration (up to 72% retention). Thermal exposure at 200°C, intended to break down polymers, instead densified the cake with residue deposition, reducing post-steaming permeability by 5-30% depending on PSD, though wire-wrapped screens with 100-150 μm slots mitigated losses. Plugging occurred primarily at the sand-cake interface, emphasizing the need for near-screen management. These findings support preventive measures to minimize plugging and optimize thermal performance. This study aims to help engineers understand the key factors influencing screen plugging and the resulting high differential pressure drop between injectors and producers. The insights gained support the implementation of preventive measures to avoid or minimize screen plugging, improving overall system performance and reliability.

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Overcoming Field Development Challenges in the Ubaque Formation: Insights from an 8-Well Horizontal Drilling Program in Colombia’s Carrizales Norte Heavy-Oil Reservoir. A Case Study

Carrizales Norte is a heavy-oil development in Colombia’s Llanos Basin targeting the Ubaque Formation, a sequence of permeable sandstones interbedded with shales and mudstones. The reservoir stores significant hydrocarbons but presents challenges, including early water breakthrough and sand production. This paper discusses the results and lessons learned from an 8-horizontal-well development program in this complex reservoir, highlighting the difficulties of managing these geological conditions.

Facing challenges with cased and perforated (C&P) wells, the operator initiated detailed evaluations to optimize the lower completion design for horizontal wells, focusing on sanding and high water cut issues to improve project economics. A sand control design study, including large-scale testing, was conducted to select the best standalone screen solution, while a technology assessment determined the most effective water control mechanism. Of the eight wells drilled, five utilized the Autonomous Inflow Control Valve (AICV) technology with direct wire-wrapped screens (DWWS) and bonded swell packers, seamed slotted liners (SSL) were installed in two and one well was completed with a hybrid of SSL and straight slotted liners.

The sand control evaluation focused on defining the sand box within the development area by analyzing 35 sand samples from five existing cased and perforated (C&P) wells. The analysis determined the variation in particle size distribution (PSD), particle shape, and composition of fines. Sand retention tests (SRT) were conducted to identify the optimal aperture size and compare the relative performance of seamed slotted liners (SSL) and DWWS. The wells, drilled with lateral lengths ranging from 1,000 to 4,600 ft, faced challenges due to the dipping formation. SSL wells were drilled first, placing them farther from the oil-water contact (OWC), while the Autonomous Inflow Control Valve (AICV) wells were drilled closer to the OWC, in more challenging conditions. The results demonstrated effective sand control, underscoring the importance of a comprehensive sand control design workflow. The AICV wells exhibited superior water control capabilities, successfully managing water production across all wells. SSL wells, even though not achieving the same level of water control as the AICV wells, still exceeded the operator’s original expectation and proved to be a cost-effective sand control means if designed properly. These findings emphasize the significance of selecting appropriate technologies based on reservoir conditions to optimize sand and water management.

Field production data highlights the importance of thorough studies and analysis to ensure the success of greenfield developments. The AICV technology has improved reservoir management by improving water-cut behavior in very challenging conditions; exhibiting exceptional water control despite being placed much closer to the OWC. Such results have allowed the operator to optimize the use of water handling facilities and disposal wells, improving project economics. Additionally, this technology helps reduce greenhouse gas (GHG) emissions by lowering energy requirements per well, thereby positively influencing both field development and overall project economics.

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The evolution of the design, evaluation, and monitoring of standalone screens

This paper aims to comprehensively introduce the historical, present, and future landscape of standalone screens’ design, and evaluation. The evolution of sand control screen design, testing, and implementation is explored, with a focus on its role in overcoming the challenges posed by heterogeneous geological formations and complex EOR strategies. Field case data will be used to illuminate the need for a more scientific approach to sand control engineering.

As operators venture into increasingly complex and heterogeneous formations, precise sand control engineering becomes imperative. This paper will delve into the historical standalone screen design, highlighting its advantages and drawbacks. Through field case examples, we will underscore the necessity for a more scientific approach. A comprehensive sand control design cycle—from information acquisition and lab testing to data analytics, manufacturing, field installation, monitoring, and post-performance analysis—will be elucidated.

Since 2017, the first attempt to optimize the standalone screen design has led to the development of a sand control best practice. The best practice outlines the guidelines and steps that must be followed on the sand control design, evaluation, and monitoring for future pads. The guidelines have been successfully implemented in the field with remarkable success and no failure to report to date. The guidelines specify the sampling method, the testing requirement to identify the sand variation within the studied sandbox, and selection criteria and evaluation testing through sand retention testing. The guidelines specify the manufacturing tolerances for each screen type. Additionally, the monitoring details for wells completed with sand control and adjustment of the best practices based on the monitoring data are outlined in the guidelines. This paper shares the rich history and lessons learned from sand control design from two fields where different standalone screens are used as the primary completion method.

Designing and optimizing the sand control screens for wells is a formidable challenge, given the intricate nature of downhole environments. This paper conveys lessons and learns from field case studies to the industry, shedding light on the complexities and offering guidance for future sand screen engineering. The insights shared aim to contribute to the continuous improvement and advancement of sand control practices in the global hydrocarbon recovery sector.

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State of the Art for High-Rate Groundwater Sand Control: Design, Fabrication, Installation, and Field Performance

This presentation focuses on the state of the art for selecting and designing sand control methods for groundwater applications, and the delicate balance of field practices with geological and hydrogeological conditions. It examines the design, manufacturing, and implementation of sand control across various applications such as mine dewatering, solution mining, disposal, and municipal water wells. By reviewing case studies, it highlights the importance of characterizing the sand box and sandface interval for effective screen design. Unique challenges in certain applications, like solution mining and acid leaching, require specialized techniques. Once screen sizing for solid retention is determined, selecting proper sizing for target rates is crucial. The presentation showcases different fabrication techniques and industry best practices for field implementation and completion through various case studies. By sharing lessons learned, the presentation aims to enhance sand control practices in the global groundwater sector.

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Technology focus: Sand Management (2024)

With the resurgence of drilling activities post-COVID-19, there is a growing interest in refining existing technologies and exploring new ones to discover cost-effective and reliable solutions for developing aged and more-challenging new reservoirs.

Although approaches may vary slightly depending on the unique characteristics of reservoirs in different regions, the general trends are conceptually similar. Drilling longer wells, increasing the number of fracture stages, and completing multiple zones in complex stacked reservoirs, along with optimizing multilateral wells with sand control to enable long laterals in stacked reservoirs, have emerged as key focuses of the industry.

Drilling longer wells introduces several challenges, including managing installation loads, ensuring proper wellbore cleanout, and ultimately producing effectively and uniformly from extended laterals that drill through heterogeneous reservoirs with varying sand facies. While liner flotation is effective in reducing installation loads and improving wellbore cleaning, it presents challenges when used in conjunction with conventional sand-control screens.

Sand control and flow control are becoming more integrated to offer solutions for effective production from longer laterals. Flow segmentation helps prevent premature failures caused by gas or water breakthroughs or localized high rates causing erosion. Paper SPE 218074 is a good example of using flow-control devices to enhance the reliability and longevity of sand-control systems.

Stacked reservoirs have always posed challenges in terms of zonal isolation and sand-control design. Higher fines content and silty sand with complex reservoir conditions leads to less interest in standalone screens because of the high risk of plugging and failure in such developments. Even though gravel packing is effective, it poses several technical and implementation challenges. The complexity of sandface completion, with varying sand sizes, pressures, and fluid properties, makes these wells particularly difficult to complete. Paper SPE 214914 offers a good case study of such a complex completion successfully implemented in the field.

Despite all this, the fundamentals of screen design and implementation remain the same. Screen plugging remains one of the major challenges in the sand-control industry. Rigorous testing of sand-control media to verify retention properties, erosional resistance, integrity requirements for the installation-loading and lifelong-loading scenarios, and plugging resistance are critical aspects of any sand-control qualification. I strongly recommend reading paper IPTC 23690 for a detailed understanding of the screen-qualification process and the design of screens for target sand facies.

Also, it is crucial to remember that no screen is completely immune to plugging. The unintended consequences of a change in drilling/completion fluid or cleanout process could lead to screen plugging. It is always important to test and validate the effect of any change in fluids or completion practices on sand-control performance.

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Impact of Inflow and Outflow Rate Control to Minimize Freshwater Usage: Historical Canadian Steam-Assisted Gravity Drainage Operations versus Numerical Simulations

This work delves into the effects of utilizing flow control devices (FCDs) to manage inflow and outflow rates on the performance of steam-assisted gravity drainage (SAGD) wells. The focus is on the impact of FCDs on enhancing oil production and reducing the cumulative steam oil ratio (cSOR). A retrospective analysis is conducted using historical data from Canadian SAGD operations to assess the impact of different flow control strategies. Additionally, numerical simulations are performed for various reservoir types, including homogeneous, simple with shale barriers, and heterogeneous reservoirs. FCDs are simulated based on findings from published flow-loop experiments. The primary benefit of incorporating flow-loop experiment data into the simulation lies in creating a mechanistic model grounded in physics as opposed to relying on empirical correlations. By comparison of the outcomes of both real-world data and numerical simulations, this study examines the influence of different flow rate control strategies on SAGD performance. Analyzing historical data extracted from a database encompassing seven major SAGD projects in Western Canada revealed that the optimal approach to enhance oil production and reduce cSOR involves the joint utilization of liner-deployed inflow control devices (LDICDs) and liner-deployed outflow control devices (LDOCDs). Given the limited availability of public information concerning the technical intricacies of flow rate control strategies and their implications on SAGD well performance, a series of simulations across diverse reservoir scenarios were conducted to investigate the mechanisms underlying the impact of FCDs on SAGD well performance. The numerical simulation findings revealed that the combined deployment of LDICDs and LDOCDs effectively managed hot-spot zones, where the inflow rate exceeded that of other sections along the producer well, leading to improved steam distribution. These results showed a potential increase in oil production of up to 26% and a reduction in the cSOR of up to 17%. This research endeavors to enhance our comprehension of how flow rate control through FCDs influences the performance of SAGD wells. The primary objective is to pave the way for more efficient well designs that contribute to reduced greenhouse gas (GHG) emissions, aligned with climate change mitigation goals.

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A practical workflow to design inflow control devices in SAGD projects to increase production and lower fresh water usage

This paper discusses the significance of inflow control devices (ICDs) in steam-assisted gravity drainage (SAGD) operations and their impact on well performance in different reservoir heterogeneities and qualities. The study focuses on investigating the specifications of ICD design using a numerical flow simulation model and flow rate versus pressure data obtained from a flow-loop experiment. The key advantage of employing flow-loop experiment data in the simulation would be a physics-based mechanistic model rather than using empirical correlations.

The research collects core analysis data from three wells and particle size distribution (PSD) data from four wells in the same location. Permeability estimation is conducted for each PSD using a previously developed correlation. These data and other real data are used to construct the reservoir model, and the performance of liner deployed (LD) ICDs is compared by assigning flow-loop data to the simulation.

By employing a relatively conservative production approach with subcooling between 10 °C and 15 °C, the cases with LDICDs demonstrate higher oil production rates, improved steam conformance, and lower cumulative steam oil ratios (cSOR) compared to the case without LDICDs. However, in a relatively challenging production scenario with subcooling between 1 °C and 5 °C, the case without ICDs cannot be simulated at the desired subcooling temperature and the cases with LDICDs improved the well productivity. LDICD#1 is identified in both scenarios as the best case due to its enhanced steam conformance and higher oil production rate.

Compared to the case without ICDs, using LDICD#1 at higher subcooling temperatures leads to a 17 % increase in oil production rate, while reducing cSOR and natural gas usage by 8 % and 10 % respectively. Similarly, at lower subcooling temperatures, the case with LDICD#1 shows a 21 % increase in oil production rate and reductions of 12 % and 17 % in cSOR and consumed natural gas respectively, compared to the case without ICDs.

The findings highlight the effectiveness of LDICDs at various subcooling levels and their potential application in SAGD projects to reduce freshwater usage and greenhouse gas emissions. Completion and production engineers can benefit from a better understanding of relative production performance to develop more effective operational designs.

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Data-driven analysis of using flow control devices and extended reach wells on SAGD well performance

The industry’s current trend to reduce Capital Expenditures (CapEx) and to minimize the environmental impacts has led to drilling long lateral wells and developing key innovative tools like Flow Control Devices (FCDs). This study analyzed the relative performance of various FCD deployments using data from major Steam-Assisted Gravity Drainage (SAGD) projects in Western Canada, spanning from 1997 to mid-2022. The goal is to investigate the impact of FCD deployment and increasing the lateral length on SAGD well performance in terms of boosting oil produciton and lowering cumulative Steam Oil Ratio (cSOR).

This paper utilizes a normalization technique to evaluate the production history of wells, considering geological and operational parameters. Following our confidential conversations with experts in the industry, wells exceeding 850 m in lateral lengths are labeled as “long”, while those below 850 m are labeled as “short”. Eventually, normalized oil production and cSOR for all wells are analyzed. A comparison is made between short and long wells that are completed or retrofitted with FCDs, giving an insight into the role of completion design on the relative performance of SAGD wells.

Reservoir thickness and reservoir quality are assessed for each well using contour maps and Gamma Ray (GR) log images. These images are digitized using image processing codes developed in our study. On average, across all projects, wells equipped with FCDs produced up to 52% more normalized oil than those without FCDs, and cSOR decreased to 18%. Long wells, on average, had lateral lengths 38% greater than short wells and produced 18% more normalized oil than all short wells. When comparing long wells with and without FCDs, the normalized oil production is improved by up to 36%, and cSOR is lowered by up to 17%. Furthermore, comparing long wells with FCDs to short wells without FCDs reveals that the normalized oil production is improved by up to 96%, and cSOR is lowered by up to 26%. The results highlight the synergistic benefits of combining longer wells with FCDs to improve normalized oil production and cSOR. The historical production analysis show that installing FCDs is the key enabler and an innovative strategy to increase productivity, reduce cSOR, and make longer wells more productive.

The findings indicate that FCDs might increase oil production and decrease cSOR for SAGD well-pad developments, allowing operators to reduce Greenhouse Gas (GHG) emissions intensity. The findings may be used to examine paradigm shifts in the development of heavy oil deposits as technology advances while keeping the project economics into account.

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Flow Control Device and Liner Floatation: Key Technology Driver in Extreme Extended Reach SAGD Wells

Pursuing more cost-effective well construction and reduced surface footprint has prompted Western Canadian operators to explore extreme extended reach drilling (ERD) wells. However, this endeavor faces a critical challenge: most heavy oil reserves are relatively shallow, resulting in the unwrapped reach ratio (the total horizontal length when projected on the horizontal plane to true vertical depth (TVD)) of more than seven. Therefore, to drill ERD wells, two crucial technical challenges must be tackled: successful liner installation, and efficient steam distribution along these long laterals to enhance production.

This paper delves into the solutions for these challenges and a case study showcasing the recent drilling of a steam-assisted gravity drainage (SAGD) extreme ERD well. While floating liners are a known method for extending well reach, they are uncommon in SAGD wells. However, some companies have started exploring the use of floating liners in SAGD projects due to their potential to greatly expand lateral well length, reducing footprint and increasing the oil recovery from any one well pair. By floating the liner using plugged flow control devices (FCDs), gentler running procedures can be employed to achieve TD without risking the integrity of the liner. Moreover, utilizing FCDs in floating liners improves steam conformance and oil production while reducing the cumulative steam oil ratio (cSOR) during the production phase.

Modeling results can enhance our capabilities in planning shallower SAGD wells with longer productive sections in the future, with (as described herein) horizontal liner lengths of 1700m and true vertical depths of 240m. The modeling results show that floating liners using plugged FCDs reduce torque by an average of 22% and bottom hole torque by 28%, while also decreasing drag by 16% on average, and bottom hole drag by 17%. These findings indicate that floating liners with plugged FCDs offer a promising solution for SAGD and CSS extreme ERD wells limited by liner installation forces. Furthermore, wells with FCDs in uplifted cases displayed a remarkable upswing of 57%, while concurrently, cSOR demonstrated a noteworthy decrease of 18%. Uplifted cases are identified when wells were completed or retrofitted with FCDs and showed increased oil production compared to neighboring wells.

The successful implementation of floating liners with dissolvable or meltable plugs on FCDs enhances confidence in future SAGD extreme ERD wells. The implementation of FCDs in extreme ERD well designs could contribute to reduced greenhouse gas (GHG) emissions, aligning with efforts to combat climate change and minimize environmental impacts. The study’s findings elaborated on driving paradigm shifts in the development of heavy oil resources as technology advances, while considering economic factors.

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Technology focus: Sand Management (2023)

As drilling and completion activity resumes post-pandemic, the sand-control market faces several logistical challenges. Inflation and supply-chain interruption concerns are expected to continue into 2024 because of high volatility in raw material pricing amplified by geopolitical tensions in Europe and the South China Sea. As oil price strengthens, consumer preferences shift and more operators investigate newer technology and focus more on performance than price.

Despite these factors, the fundamentals of sand control and sand management remain the same. As more-challenging reservoirs are being developed and new difficulties arise, however, more engineers are questioning the conventional sand-control aperture-sizing wisdom.

Any sand-control effort aims to manage solids production while creating the fewest restrictions to fluid flow. To assure that sand-control efforts meet these goals throughout the life cycle of the wells, engineers must design them in a way that can withstand the forces of nature, doesn’t erode with high and localized flow, doesn’t corrode with the harshness of produced fluid, and doesn’t mechanically deform during installation and life-cycle loads. If you are interested in diving into these design processes, paper IPTC 21158 provides insight.

With the higher adaptation of flow-control devices in recent years to improve flow segmentation and reduce the premature failure of sand control because of highly localized flow, flow-control-device implementation is becoming an integral part of sand-management strategy. More papers every year discuss the design process and field implementation of various kinds of flow-control devices along with sand controls. Paper SPE 210299 provides good insight into some of the field challenges and results of implementing flow-control devices with sand control. As always, monitoring for sand and solid production is key in any sand-management effort to assure the integrity of the system and maintain the containment of the fluids. In the past year, several papers focused on monitoring, including discussions of new technologies and presentations of field case studies. Paper IPTC 22989 is among the interesting papers in this subject.

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