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.

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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 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.