How to Evaluate Dissolvable Rubber Element Sealing Performance

To evaluate dissolvable rubber element sealing performance, start with the real downhole conditions. Then measure pressure holding, leakage, hardness, compression set, temperature response, and dissolution timing against written acceptance limits. A dissolvable rubber element must hold pressure during pumping, then degrade on schedule so the wellbore opens without retrieval. A catalog rating alone cannot confirm that. Batch-level test data, representative fluids, and staged trials give you much stronger evidence. In this guide, I walk through each step in plain terms, so your engineers and buyers can compare suppliers using facts rather than claims.

Define the Sealing Requirement Before You Test

Start With the Downhole Operating Envelope

I think a good review starts with the well, not the book. Write down the depth, temperature, differential pressure, weight, and size of the casing. Also write down the type of fluid used, the seal's length of time, and how it is set up. After that, enter the conditions you want for dissolution to happen, such as the brine's temperature and saltiness. A dissolvable rubber element might work fine in mild water, but it might not work the same way in hot, salty flowback. All of your engineers, customers, test lab, and provider will be able to work together toward the same goal if you put these details in a single table. Quotes that look like they belong together but are actually about different things are also stopped by the table. You should only use a supplier's rating as a starting point if they can't tell you what conditions are implied by it.

Turn Requirements Into Acceptance Criteria

Needs are only useful if you know how to measure them. Fix each condition so it can only pass or fail before you start testing. Sometimes there are limits on how fast something can leak, how long the pressure can stay in place, how much permanent deformation can happen, how much can be pushed past the backup ring, and the window when the dissolution is complete with a residual mass ceiling. Being hard is also on the list. The range that many buyers use is something like plus or minus 3 Shore A points on the drawing. They then compare each lot to that range. Everyone stays safe when rules are written down. This seller knows what to offer, and your team can say no to many of them without having to fight about what they mean. Also, I believe it should say which test method was used for each limit. For example, ASTM D2240 for hardness and ASTM D395 for compression set.

Separate Static Sealing From Cycling Loads

A seal that works well on a bench might not work at all in the field. Pumping steps can be used to make speed changes, pressure ramps, temperature changes, and small tool moves. Backward pressure can show up when a stage above lets go. Each load puts force on the part in a different way. A steady test shows that the seal is at its baseline. A cycling test checks to see if the permanent set lets water leak through or if the compound moves back into place. A moving test checks to see if the part moves or breaks. How the tests were loaded is the first thing I look at in a test report. "One steady hold at room temperature" isn't enough information to answer your question. Ask for numbers that fit your treatment plan, like the cycle count and ramp rate.

Understand Material Composition and Dissolution Behavior

What Goes Into a Dissolvable Rubber Compound

Dissolvable rubber elements are made up of elastomers or polymers that hold the other materials together. The right amount of strength and controlled breakdown is achieved by adding curing agents, reinforcements, soluble fillers, and chemical modifiers. To make the design work for everyone, there isn't just one formula that does. Temperature, pressure, fluid chemistry, and the schedule of dissolution all have their own effects. Isolating the element must be physically sound, and it must then break down without leaving any extra stuff behind. This is the main problem, which is easy to explain but hard to solve. Dissolvable rubber elements that work with this balance are made from HAGRIEN Engineered rubber materials. They break down and seal when they do, so you don't need to get them back. Ask the supplier to write down what kind of compound it is and how it breaks down.

Fluid Compatibility and Dissolution Timing

Breakup is more of a time profile than a yes-or-no claim. It's important to find out how much the material weighs, how its shape changes, how strong it is, and how much is left over. It is important to use the right fluids for the job. Some examples are oil-based systems, breakers, surfactants, friction reducers, alkaline or acidic fluids, and suspended solids. The amount of salt, pH, flow, thickness, and surface area can all change how quickly a dissolvable rubber element breaks down. Compounds that dissolve in water react to other fluids, while compounds that dissolve in oil react to water. Pick the type that fits your plan the best. Late in the process, keep an eye out for swelling, softening, cracking, and uneven wear. Compounds that break down quickly get the flow going again more quickly, but they can't handle as much contact. Compounds that break down more slowly make isolation last longer, but cleanup may take longer.

Hardness and Compression Set Control Batch Consistency

Checking the hardness and compression set of a lot can help you quickly tell if it will behave similarly to the last one. ASTM D2240 says that a durometer changes the way the element presses against the case to measure hardness. You can see how much the material doesn't return after being squeezed by using ASTM D395. Large changes in either number can make seals from the same set of tools not work the same way, which makes the assembly take longer. You can pick the right hardness for your needs with HAGRIEN rubber elements by looking at the pressure and clearance. It is between 60 and 90 Shore A hard. Do not just copy a number from a spreadsheet; ask for results at the lot level using the method that is named on the report. Your quality team can tie each batch of dissolvable rubber elements to a unique record that can be tracked back to the COA.

Test Pressure, Temperature, and Mechanical Behavior

Pressure Holding and Leakage Measurement

The real thing should be the same as the pressure test. Before and after the test, write down the hold time, the ramp rate, the cycle, the worst difference pressure, the leaks, and how the reverse pressure behaved. If you want to hide problems that a real casing can show, use casing, fluid, and surface finish that are very close to the real thing. ISO 14310 talks about packers and bridge plugs and gives validation marks that show how well a tool design has been proven. This helps you write a test plan. After that, look at the part to see if it has any cracks, tears, or permanent bends. It's not a success to pass on leakage with a broken part; it's a red flag. Ask the supplier to list the different types of fluid and pressure that each rating is good for.

Extrusion Resistance and Element Geometry

When you press down on the tool and case, rubber is pushed into the space between them. The word for this is extrusion. When there are bigger gaps, rough spots in the casing, changes in temperature that make the material soften, and a lot of pressure cycles, the risk goes up. It's important to know both geometry and compound. Things like the compression ratio, the shape of the lines, and the backup structures can change the contact stress and gap security. It is possible for a good compound to break in a bad shape, and it can also happen the other way around. To properly study a dissolvable rubber element, I need more than just the material data. I also need dimensional models and instructions on how to use the tool. When picking the hardness, think about the space between the pieces. It's better for harder compounds to stop extrusion, but they might not seal as well on rough surfaces. Tests of the parts on your real tool geometry quickly show how they interact.

Pressure–Temperature Interaction

There are many things about rubber that change with temperature. These include its hardness, flexibility, compression set, response rate, fluid penetration, dissolution speed, and resistance to pressure. Describe the whole temperature range, including the lowest temperature, the highest temperature that doesn't change, any short peaks, ramp rates, and the thermal cycle. After that, read each pressure number next to its temperature. There is no way to tell how long you will be downhole by a single number for room temperature. HAGRIEN rubber elements can handle temperatures of up to 200°C, and our HTHP lab is approved by the CNAS so that certification can be tracked. Even so, I tell buyers to make sure they have the right pressure, temperature, fluid, and length for the job, since the temperature often changes along with the pressure. Put each possible dissolvable rubber element next to another and see how they react to temperature. Then, ask for leakage readings and post-test inspection notes for each temperature condition.

Compare Options and Qualify a Supplier

Compare Against Conventional and Retrievable Options

If you want to compare options, don't look at the unit price but at the total operating value. If you need to mill, drill, or retrieve conventional or drillable elements, it may take longer and there is a greater chance of debris. A dissolvable rubber element can reduce the need for that kind of help, but the fluid and temperature conditions need to be better controlled, and the fact that it dissolves needs to be proven, not just assumed. To remove retrievable packers, you need to use mechanical tools. On the other hand, dissolvable designs may be easier to get into the wellbore, especially if the well is long or has bends in it. HAGRIEN dissolvable rubber is used to make frac plugs, bridge plugs, and dissolvable separation tools that are used in multistage fracking. Getting the tool string back adds cost and risk. All at once, think about how well the seal works, how long it takes to separate, how the obstruction is taken out, how much it costs, and how it affects the schedule.

Run a Staged Verification Plan

You should use steps because one lab test doesn't usually answer the question. Before you do anything else, you should test the material to see how hard it is, how it behaves in fluids (ASTM D471), how it compresses, how dense it is, and how easily it dissolves. Next, check the parts for leaks, being exposed to temperature, cycling, compression, contact with the casing, and keeping the pressure. Third, look at your tool's shape, fluid, pressure, temperature, and isolation time. Then, change the standard based on what you saw and learned in the field and what you thought would happen in the lab. Small pilot lots can make this work, so ask each provider early on about sample and pilot lots and costs. Do not mix up your lab results and field qualifications. Keep them separate in your records.

Check Documentation, Traceability, and Delivery Fit

What a provider knows about how it handles production is shown by the data it has. What are the acceptance standards, the sizes, and the material certificates like COA, COC, and SDS? Find out the test results for each batch. HAGRIEN uses the ISO 9001, ISO 14001, and ISO 45001 systems, makes sure that the COA can be tracked, and has a U.S. company run projects in North America. That's why we know how the metal and element pieces need to fit together. There are also fixing tools, packers, and bridge plugs that dissolve that we make. In 24 hours, our team will confirm what you need. In one to three business days, they will send you a formal quote and schedule. Projects that are more difficult are approved individually. You can give us your models and numbers, and we'll make sure the plan works with how you do your work.

Conclusion

A set of evidence is the best way to judge how well a dissolvable rubber element seals. To begin, describe the downhole area. After that, turn it into limits that can be checked. When something seals and when it dissolves depend on its composition, how it reacts to liquids, how hard it is, and how much tension it has. With real fluids and casings, you need to test for pressure holding, leaks, extrusion resistance, and temperature reaction. You also need to read each number with its conditions. When deciding between options, it's better to look at their total operating value instead of their individual prices. The next step should be a staged verification process that starts with screening the materials and ends with tool-level and field proof. You can find out if results will be the same from one batch to the next by using named methods, batch-level reports, and records that you can track down. The main point is that a low price or a single pressure number can't tell you which choice is best. Full operating environment and proven consistency are the only things that can.

FAQ

1. What is a dissolvable rubber element?

An elastomer part that seals while it breaks down is called a dissolvable rubber element. It just breaks down on its own over time. This takes away the need to get it back.

2. What controls the dissolution time of a dissolvable rubber element?

The formula, temperature, fluid chemistry, salt, pH, flow, thickness, and surface area that is exposed can all change the time frame. Tests should never be done with plain water. Use the right fluids for the job instead.

3. What should I include when I request a dissolvable rubber element quotation?

Include the different types of dimensions and tolerances, the shape and size of the tool, the operating pressure and temperature, the fluid composition, the time it takes to seal, the time it takes to dissolve, the amount, the paperwork that needs to be done, and the delivery date. You'll get an idea and price that work for you once you send in the whole box.

Request a Technical Evaluation for Your Dissolvable Rubber Element Project

Write to cyrus@us-hagrien.com with your drawings, the size of the casing, the pressure, the temperature, the amount of fluid, and the data on these things. We offer dissolvable rubber elements and our production is ISO-certified. Our testing is CNAS-accredited, and you can track your order with a COA. We can suggest a compound, set up sample testing, and make a project price. Visit us-hagrien.com to find out more.

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. 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

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

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