Dissolvable Rubber Element for Frac Plug: Pressure Sealing

A dissolvable rubber element for frac plug service is the expandable elastomer that seals between the plug body and the casing wall, so each fracturing stage holds pressure during pumping. After the job, the element degrades in wellbore fluid, which removes the need for a mill-out run. Pressure sealing depends on the compound, the element geometry, the casing, and the fluid, not on a single pressure rating. At HAGRIEN, we make rubber elements for frac plug manufacturers and completion tool OEMs. In this guide, I explain how the seal forms, what to test, and how to choose a supplier.

What Is a Dissolvable Rubber Element for Frac Plug Service?

How the Element Works Inside the Plug

The part is the frac plug's closing ring. When the setting tool presses the plug parts together, the element contracts along its axis and extends until it hits the case. The circular gap is closed by that contact, so pumped fluid pushes the plug against the seal instead of going around it. Slips, cones, and the mandrel are not the same as this element. The load is held by the mandrel, which is moved outward by cones that push the slips outward. The pressure barrier is only made up of the element.

Where These Elements Are Used

They are mostly used in plug-and-perf completions. A dissolvable rubber element for frac plug designs adds another task: it has to break down when the stage is over. This means that material design is just as important as geometry. Crews set a plug, perforate, and pump a stage in horizontal shale wells and other multi-stage unconventional completions. They then do it all over again. For re-fracturing programs to work, the zones must also be kept cleanly separate. In every case, operation that doesn't need any help is important, since a plug that breaks down on its own gets rid of the mill-out trip. Plug makers and completion tool OEMs buy a dissolvable rubber element for frac plug builds and put it together with their own metal parts. The company that makes the plug controls the final assembly and the technical claims made about the product.

Why Sealing Must Last Through the Whole Job

It's a big problem when a seal holds when it's set but breaks down when it's pumped. The pressure in a frac stage can change as rates change and fluids move from slickwater to gel or brine. This can happen for hours. During that whole time, the element has to keep contact stress against the casing. If there is an early break, fluid can go to the wrong area and lose the stage. An early failure hurts the brand's name in the field for a plug maker as well. Therefore, I advise buyers to assess the stability of a dissolvable rubber element for frac plug use over time, rather than in the first few minutes of setting.

How a Dissolvable rubber element for frac plug Creates a Pressure Seal

Now that we know what the element does, the next question is how it actually makes a seal.

From Axial Load to Contact Stress

The element is squeezed between the plug parts by the setting force. Under load, rubber doesn't change much in size, so the material has to move outward. It gets bigger around until it hits the casing in a dissolvable rubber element for frac plug design. More compression makes the contact stress higher. The element is then pushed against the wall harder by differential pressure. It depends on the compression ratio how much the element has to expand to fit through the gap in the casing. This ratio determines how much contact stress the seal can hold. A small gap doesn't need much to be filled. There is a greater chance of extrusion when there is a big gap or case shift.

Factors That Change the Seal

If the seal works or not depends on a number of factors, including the inner diameter and clearance of the casing, the surface state (like scale or pitting), the shape of the element, its hardness, and the temperature. Harder compounds don't easily extrude into gaps, but they don't mold as well to rough surfaces. The more flexible a compound is, the more it flows when it is under pressure. Rubber parts from HAGRIEN range in hardness from 60 to 90 Shore A, which means we can find a compound that fits your case and anti-extrusion design. The fluid exposure affects every dissolvable rubber element for frac plug sealing case, because the seal shape can change if the rubber swells or softens during the job.

The Data to Request Before Trusting a Rating

A pressure number by itself doesn't tell you much. Ask what kind of fluid was used, the size and surface of the casing, the temperature, the hold time, and the criteria for leakage. Validation marks for packers and bridge plugs are set by ISO 14310. This means that buyers and sellers can use the same language for test results. Always ask for batch records, because just because one lot did well doesn't mean the next lot will do the same. When you order a dissolvable rubber element for frac plug assembly, it should come with data that your engineers can check, not just claims that they have to believe.

Materials, Degradation, and Performance Requirements

Material Properties That Matter

The majority of compounds for a dissolvable rubber element for frac plug applications are chosen based on five properties: toughness, tensile strength, compression set, tear resistance, and chemical compatibility. ASTM D2240 talks about hardness measured by a durometer, ASTM D412 talks about tensile testing, and ASTM D395 talks about compression set. When an element is held under load, the compression set tells you how much it fails to recover. This has a direct effect on seal retention. The precision-grade rubber materials used by HAGRIEN parts can withstand temperatures of up to 200°C. Our tests are approved by CNAS, and the full COA tracking lets a buyer look at these features one by one.

What Drives Degradation

It's not the same as shrinking, growing, or breaking into pieces. All of them are possible, but only total breakdown can clear the wellbore. The rate changes with time, temperature, pH, salinity, pressure, and the chemistry of the fluid. Most of the time, heat speeds up degradation. Depending on the compound, fluid chemistry can either speed it up or slow it down. Because of this, the part can act in two wells in different ways. I never give a single break-down time for all wells. You give us the temperature and fluid data from the bottom of the hole and then we talk with your experts about the degradation window for a dissolvable rubber element for frac plug project.

Performance Requirements for the Full Plug

The qualification process should go through the whole plug, not just the rubber. Check to see if it can handle changes in temperature, differential pressure, cycling of pressure, and working with slickwater, gels, brines, additives, and hydrocarbons. Add dimensional tolerance because an element that is too big can cause problems during run-in, and one that is too small might not seal well. The last two items on the list are extrusion resistance and batch consistency. Use a similar casing, fluid, pressure, temperature, and exposure time for the test to the real well. There should be different test plans for low-, medium-, and high-temperature wells, and the dissolvable rubber element for frac plug source should take that into account.

Dissolvable Rubber Element for Frac Plug Versus Drillable Plug Elements

The type of plug doesn't matter how well it works or what materials it's made of; here's how the different types compare.

Where Dissolvable Elements Save Time

Any plug that can be drilled needs to be milled out after the frac job. For that run, you need coiled tubing or a workover rig, time, fluid, and trash. A design that dissolves gets rid of the run when the element and other parts that dissolve as planned. Long horizontal wells, where coiled tubing may not be able to reach the toe, and rural areas where it is hard to move tools make the benefit even greater. HAGRIEN designs its parts so they can work without any help from the user. For example, a dissolvable rubber element for frac plug builds makes it easy for plug makers to get to production after the last stage.

Where Drillable Plugs Still Fit

Dissolution doesn't always work well. If the chemistry or temperature of the fluid isn't known, the timing of decline may change, and an operator may want a plug that crews can mill out on time. Some programs also need the part to be taken out mechanically to make sure the bore is clean. It is easier to plan for those wells because a standard element's performance window is not affected by the chemistry of the fluid. I think it's better for partnerships to be honest when comparing technologies than to oversell one. It is the well data, not the other way around, that should guide the choice of a dissolvable rubber element for frac plug.

Matching Plug Type to the Completion Plan

Start with the plan. Write down how many stages there are, how long each one takes to pump, when it stops pumping, and when the expected flowback date is. The element has to stay in place for as long as it's supposed to and then break down before production needs the bore. Add up the time and money it takes to do a mill-out run and the price of the plug. Then look at the limits for access and debris. As long as the well data are known, the fluids are under control, and the operator doesn't want to get involved, a dissolvable rubber element for frac plug makes sense.

Selecting a Dissolvable Rubber Element for Frac Plug and Working with a Manufacturer

Define the Well and the Interfaces

A data sheet is the first step in the selection process. Write down the size, grade, and inner diameter of the casing, as well as the setting depth, temperature, differential pressure, pressure cycles, separation length, fluid chemistry, and timing of the flowback. Include the plug drawing, which should show the gland's size, the design of the backup ring, and the metal parts' surface finish when they fit together. Small differences in dimensions can change how hard it is to put something together and how much force is needed to set it in place. If you give us the design of the tool, we can change the shape of the seal to fit your plug instead of just making it fit a print. For frac plug software, that method is appropriate for a dissolvable rubber element for frac plug.

Testing, Documentation, and Traceability

Ask all of your suppliers to give you the same set of information: test results, storing instructions, certificates, specs, and a way to track the goods. HAGRIEN follows the rules set by ISO 9001, ISO 14001, and ISO 45001, and does tests in a high-temperature and high-pressure lab that is approved by CNAS. We offer COA tracking, and you can get COC, SDS, and inspection records from us if you ask. These papers help your quality team approve a supplier, back up audits, and find the source of a problem in the field. They also give your sales team data that can be used to back up the plug's technical claims.

From Samples to Supply

In a typical path, there are five steps: reviewing the application, making sure the requirements are met, choosing the material and geometry, testing prototypes in a simulated downhole environment, and making a few units before placing bulk orders. Within 24 hours, we check the needs and the technical list. Within one to three business days, we send an official quote and delivery plan. Projects that are complicated need special approval. Weekly reports on results are good for North American projects, and our U.S. office helps with coordination. We also offer machining parts, dissolvable magnesium alloy bars, and dissolvable bridge plugs. This way, we can plan metal parts and each dissolvable rubber element for frac plug order together, so there is less time spent waiting for parts.

Conclusion

The well doesn't need a mill-out run because a dissolvable rubber element for frac plug use covers each stage while pumping. The seal is made when axial compression changes into radial contact stress. It is not based on a single pressure rating, but on the compound hardness, geometry, casing condition, and fluid exposure. There are things like compression set and tensile strength, as well as temperature and fluid chemistry, that affect how long the element lasts and whether it clears on time. Dissolvable designs keep people from having to go into deep or long wells, and drillable plugs work well when the fluid conditions aren't known. Complete well data, full-plug testing, batch-level paperwork, and a way to go from concept to pilot production are what sound selection is based on.

FAQ

1. What does a dissolvable rubber element for frac plug do?

When the pump is running, it seals between the plug and the casing, keeping one stage separate from the next. It breaks down in the wellbore fluid after the job is done, so crews don't have to mill out the plug.

2. What controls dissolution time?

Not only does the compound itself matter, but so do the temperature, pH, salinity, pressure, fluid chemistry, and exposure time. Before we suggest a combination, we look at the data from your well.

3. Can one element suit every fracturing fluid?

No, it depends on the compound and the fluids being used. Before getting approval, test it with your own slickwater, gel, or brine.

4. What hardness and temperature range does HAGRIEN offer?

Our rubber parts can withstand temperatures up to 200°C and have a Shore hardness range of 60 to 90 Shore A. All the way back to the COA, each batch has a full history.

Request a Custom Dissolvable Rubber Element for Your Frac Plug

Do you need a dissolvable rubber element for frac plug manufacturer who can work from your plans? Send HAGRIEN information about your casing, including the setting depth, temperature, pressure, time of isolation, fluid data, and an estimate of how much you need. In 24 hours, we'll confirm the technical list and the requirements. For more information on a product, email cyrus@us-hagrien.com or go to us-hagrien.com. With every dissolvable rubber element for frac plug project, we offer samples, validation testing, and OEM production.

References

1. ISO 14310, Petroleum and Natural Gas Industries – Downhole Equipment – Packers and Bridge Plugs, 2008

2. ASTM D395, Standard Test Methods for Rubber Property – Compression Set, 2018

3. ASTM D2240, Standard Test Method for Rubber Property – Durometer Hardness, 2015

4. ASTM D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers – Tension, 2016

5. ASTM D471, Standard Test Method for Rubber Property – Effect of Liquids, 2016

6. ISO 23936-2, Petroleum, Petrochemical and Natural Gas Industries – Non-metallic Materials in Contact with Media Related to Oil and Gas Production – Part 2: Elastomers, 2011