FADE is a family of dissolvable metal alloys and thermoplastic materials, which dissolve or degrade when coming in to contact with common wellbore fluids, including fresh water, brine, oil-based mud and acid.
Our dissolvable materials allow for temporary construction in the well and are designed to disappear within hours or days when in contact with the appropriate fluid. This simple solution leads to reduced costs, improved safety, and lower emissions.
Dissolvable inserts for liner and inflow control devices
Some wells may be planned with inner strings in the reservoir liner to enable placement of fluid in the reservoir section. With temporary plugs in the reservoir liner, or directly in Inflow Control Devices (ICDs) and Screens, the operation can be carried out without the use of inner strings, which ultimately saves cost and rig time.
Design is customized to each application, with a variety of nozzle diameters and material grades available. Dissolution time can vary from 3-25 days depending on requirements The inserts will fit both ICD and AICV screens.
Temporary isolation of the wellbore
Dissolving balls can be used to eliminate the need for wireline runs associated with packer setting. Typically, a seat is installed on tubing below a packer and a dissolvable ball is pumped from the surface. Once the ball lands on the seat, the well can be pressurized to activate the packer and test from the annulus. After a pre-determined number of hours or days, the ball will dissolve and pass through the seat and continue to dissolve until the reaction is complete and nothing remains.
The outer diameter of the ball and the inner diameter of the seat are designed with a minimum overlap, depending on required pressure. Typical overlaps are from 0.100” to 0.125”. If required, the seat can be made of cast iron and be milled out at a later stage.
Ball activation of sleeves
Frac or stimulation sleeves are activated with balls. The operation starts with pumping the lowest stage closest to the shoe, first, enabling a short section of the reservoir to be stimulated.
Sequentially larger balls are then pumped, which isolate the stage below, allowing for an efficient stimulation operation without the need for running and pulling plugs between each stage.
Using dissolvable materials eliminates the need for producing balls back to the surface, leaving the wellbore open for future well interventions.
The design process
Designing tools with dissolvable material requires an in-depth knowledge of how the degradable material behaves downhole in the well.
At Marwell, our comprehensive 4-stage design process is based on years of experience with dissolving materials, which combined with our laboratory set-up, ensures that final designs meet downhole requirements.
We review and evaluate the functional requirements of each application, considering the required strength or pressure, geometry and minimum and maximum dissolution times.
In addition, the specific downhole conditions such as temperature and the types of fluids that will be exposed to the material at various times are considered.
Design and simulation
The mechanical properties of the degradable material are now known and the mechanical design is carried out. Unlike normal design engineering, the dissolution time is also included. In the design process, which is based on previous testing and varies with temperature, material and fluid type.
Ensuring that the properties of the final product are consistent every time, the dissolving material is batch of LOT# tested for material properties and dissolve rate
Laboratory qualification testing
This is the heart of the design validation process. The laboratory testing verifies that the final design meets the function requirements downhole. Testing is carried out with actual or recombined fluid.