MazeFlo™ technology enables a sand control screen to self-mitigate mechanical damage and improve reliability in sand-prone well production. A self-mitigating screen uses redundant sand control screens and compartment baffles to restrict the effects of any mechanical screen failure to a local compartment. The hydrocarbon flow continues intact through the remaining undamaged screen compartments. This innovative, patented technology is being commercialized in collaboration with a selected service company. This paper reviews the initial design and development of the self-mitigating screen prototype. The screen design balances flow hydraulics, well performance, mechanical integrity, and manufacturing complexity all while maintaining practical screen dimensions. Successful self-mitigation, after failure of an outer screen, requires that the incoming sand packs a compartment to shut off the flow path before any significant erosion occurs along the flow path to the redundant inner screen. The baffles are configured to both redirect fluid momentum from any "hot spot" inflow at the outer screen and impose a minimal friction loss during production through undamaged compartments. Each component in a compartment is designed to sustain erosion from the incoming sand of a failed outer screen. The offset outer and redundant inner screens are sized to minimize the impact on productivity when compared to conventional screens. The mechanical strength of the self-mitigating sand screen is also targeted to be equivalent to conventional screens. Development of the self-mitigating screen prototype is proceeding and includes extensive qualification by multiple modeling techniques and physical testing. The innovative, self-mitigating capability expands the current operating limits of screens in sand control completions. In a broader view, the self-mitigating screen enhances overall reliability and longevity and can be integrated with other emerging technologies such as openhole zonal isolation, inflow control, and intelligent wells for enhanced production flexibility. MazeFlo sand screens will expand ExxonMobil's suite of innovative sand control solutions that include Alternate Path® technology, NAFPacSM process, openhole gravel packing with zonal isolation, and customizable sand control for extreme length completions and injection conformance.

No abstract

Sand control reliability becomes increasingly important when combining challenging well conditions with the expectations of high flow rates, reduced well counts, and rising costs. Sand screens, the final sand control barrier, have been a critical element to assure long term well reliability. Any screen damage along the well may allow sand ingress and adversely impact the overall production. Preventive (flux limitations) and reactive (choking) methods can reduce the risk of downhole screen damage under complex producing environments, but these methods are unable to mitigate all risk. A step change in screen design to enhance sand screen reliability is needed which can also maintain simple and economic completions.MazeFlo™ technology, currently under development, was invented to be adaptive to downhole uncertainties and to self-mitigate screen damage. The technology utilizes a redundant sand screen and compartment maze to constrain local sand ingress caused by screen damage without interrupting well production. A prototype screen has been designed and fabricated.A series of hydraulic and mechanical tests were conducted to validate the prototype design. Both compartment and redundant screens are qualified in flow friction, erosion resistance, and mechanical integrity. A field trial has been designed to demonstrate the screen installation, downhole self-mitigating capability, and sustained production. Operationally, the innovative and robust screen design will appear and run similar to conventional screens.Successful prototype development will lead to a 2 3/8-in MazeFlo screen ready for use in remedial workover applications. The design philosophy and qualification process are being extended to larger screen sizes for broader applications. The adaptive approach implemented in this novel sand screen establishes a new milestone to enhance sand screen reliability. The collaboration between operator and service supplier enables effective commercialization of innovative technology for the next generation of sand control completions.

No abstract

Sand screens subjected to increasingly complex and challenging environments are pushed to the limit of maintaining reliable sand control. Both preventive and reactive methods have considerably improved sand screen reliability, but the effectiveness of these methods in sustaining production is still limited by downhole uncertainties. Consequently, innovative sand screens are required to enhance sand control reliability, while maintaining operational simplicity. MazeFlo™ is one recent technology innovation from ExxonMobil designed to meet this challenge. MazeFlo technology takes a self-adapting approach to enhance sand screen reliability. The technology utilizes a redundant sand screen and compartment maze to self-mitigate sand breakthrough caused by screen damage. The sand ingress is restricted in a local compartment without interrupting the overall well production. A 2?" prototype screen has been designed, fabricated, tested, and qualified for field installations. This paper will highlight the qualification of this new screen through a series of mechanical tests and concludes with a field test designed to subject the screens to an extreme producing environment. The mechanical performance was evaluated under various load bearing conditions including collapse, burst, bending, torsion, tension, compression, and push-off. The results proved that there were no constraints to the self-mitigating capability of this new screen when subjected to this rigorous testing program. The field qualification test was conducted in an existing sand-prone well producing at high local flux to demonstrate screen functionality in an "uncertain" production environment versus a controlled, laboratory experiment. The field test demonstrated successful installation, downhole self-mitigating capability, and sustained sand-free production. This unique, self-adapting technology unlocks the limits of sand screen reliability and provides an innovative and unique option for sand control completions to sustain production. The dedicated collaboration between operator and service supplier delivers continued success in developing innovative technology from concept to field installation.

Sand screens often serve as the primary barrier to sand production from weakly consolidated reservoirs. Screen technology has improved significantly in the areas of sand retention, mechanical integrity, and quality control. As future field developments trend towards more hostile environments, requiring fewer wells at higher rates, the overall reliability and longevity of sand screens will be increasingly more important in this high cost environment. This paper introduces a self-mitigating sand screen technology, MazeFlo™, that uses redundant sand control and compartment baffles to improve reliability and longevity for sand-prone well production. The technology self-mitigates downhole screen damage by isolating the effects of any mechanical failure of the screen to a local compartment, while allowing continued hydrocarbon flow through the undamaged sections. The compartment maze is comprised of baffles and tortuous flow paths that balance the incoming flow momentum from the outer screen. This flow redistribution mitigates risk of inner screen failure, while posing no additional plugging risk over conventional screens.These self-mitigating screens reduce the frequency of sand-related workovers, extend well production, and increase recovery. Due to its simplicity and unique passive control capability, self-mitigating sand screens will expand the applicability of less complex and more cost effective standalone screen completions. Self-mitigating screens can also be easily combined with other emerging technologies such as zonal isolation and inflow control devices.

No abstract

Openhole completions are often selected as the preferred completion technique to maximize reservoir flow potential and provide reliable, high capacity, low skin completions. In many environments, these completions will also require some form of sand control. To meet development objectives, operators are continually challenged to select, design, and install fit-forpurpose completion strategies to optimize ultimate recovery for these fields. These challenges necessitated the creation of new practices, procedures, and hardware to ensure consistent delivery of reliable wellbores, across the entire organization, to achieve long-term, economic success.ExxonMobil embarked on a multi-year initiative to establish and sustain a disciplined, systematic approach to sand control completion design, job execution, and performance assessment. The effort included the development, qualification, and deployment of selective, enabling completion technologies. Additionally, comprehensive engineering and operational guidelines, as well as, in-depth training were delivered to the worldwide engineering and operations workforce. Most significantly, the initiative is now resulting in effective and rapid transfer of learnings and best practices across the global organization. This comprehensive effort continues to focus on ensuring the right people are deploying the right technology in the right well. This paper will discuss the guiding principles associated with our overall completion practices. It will also describe a number of enabling technologies pioneered by ExxonMobil including: • NAFPac SM , a gravel pack technique that allows the operator to run the gravel pack screens in non-aqueous fluid, gravel pack the well and displace the casing to brine, all in one trip • MazeFlo™, a self healing, redundant sand screen • Internal Shunt Alternate Path Technology (ISAPT) screens with openhole shunted packers, a completion technique that enables true and selective zonal isolation in openhole gravel pack applications