Welcome to the new Navigator Nation! Stay tuned for new features and announcements.

Hdd Archives

  • « Back

    Making sense of HDD drilling fluids

    Jun/21/2018

    Why drilling fluid is essential to HDD and the mixing process

    Drilling fluids are the secret sauce on horizontal directional drilling (HDD) jobs. Drilling fluids can also be one of the most misunderstood aspects of drilling operations. Every member of your crew working around drilling operations should understand what drilling fluid is, how to mix it, the type of additives they should use for various soil conditions, how to determine pumping and pullback rates, as well as how to make adjustments on the job.

    This series of short articles will help take some of the mystery out of drilling fluids, beginning with why it is essential to HDD operations and ways to mix it.

    Why drilling fluid is important
    Here are a few of the reasons drilling fluids are used on HDD projects:

    ·  Helps extract cuttings: Failure to remove cuttings from the bore path can result in inadvertent returns (frac-out), limit distance length the drill can pilot bore, heave ground surfaces above the drill head and lead to product pullback failures.

    ·  Creates downhole stability: Drilling fluid helps the drill path keep its shape during the drilling process. Using the right type of fluid additive is also important to help a drilled hole maintain its shape when working in different soil types (drilling in sand for example).

    ·  Cools and lubricates tooling: Downhole tooling temperatures can rise quickly without the use of drilling fluids. Drill head temperatures rising above 220° Fahrenheit will permanently damage the transmitter that gives critical depth and pitch data. Drilling fluids also help keep tooling clean and reduce pullback/rotational torque pressures required to pilot out and pull product back through. 

    Drilling fluid viscosity
    You’ve now learned why using drilling fluid is essential, but it's also necessary to understand having the right viscosity (thickness) of drilling fluid.

    Drilling fluid that is too thin or light can limit the amount of cutting returns. You may still get the majority of returns, but heavier cuttings can sink to the bottom of the bore (creating a cuttings bed) and not be flushed out. After a while, this cuttings bed can create return flow issues during the rest of the drilling process (which can result in excessive product stress and inadvertent returns).

    Drilling fluid that is too thick can result in additional downhole pressure to get fluid to flow and eventually lead to inadvertent returns. Fluids follow the path of least resistance, and if the fluid is too thick — that direction is typically towards the surface.

    To check that you have the right viscosity, it’s important to measure it every time you mix up a batch of drilling fluid. You will need a Marsh funnel and cup, following these steps.

    1.  Start by filling your cup up to the fill line with drilling fluid.

    2.  Next, plug the hole in the bottom of your funnel with your finger and pour the fluid through the funnel’s screen (ensure you are wearing proper safety gloves).

    3.   There shouldn’t be any clumps of material left behind on the screen. If there is, your drilling fluid is likely not mixed correctly or fully hydrated (more on that next). Repeat until drilling fluid crests the top fill line (just under the screen) of your Marsh funnel.

    4.  Now, place the empty cup below the funnel and start a stopwatch as you remove your finger from the bottom of the funnel. You want to stop counting when the drilling fluid crests the top fill line (32 oz [.9 kg]) of your cup. This number is your drilling fluid viscosity measurement.

    You should aim for a viscosity rate of between 45 and 60 seconds for most drilling applications.

    Mixing processAlways make sure the person assigned to drilling fluid mixing is fully trained on the proper steps.

    On every new job, you should check pH levels from your water source. Drilling fluid additives (bentonite and polymers) mix better with a pH level range between 8 to 9. Municipal water will typically measure around that range. However, if you’re using water from a pond or well, the pH level will likely fall below that range. Adding soda ash will help raise the pH levels and help you use less drilling fluid products.

    When you’re ready to mix your additives with the water, powders like bentonite must be added to the hopper and liquids should be poured directly into the tank.

    Every Vermeer fluid mixing system is equipped with a bag cutter next to the hopper. Use it to split and empty the whole bag into the hopper at once. Doing it this way, instead of cutting it with a knife and slowly sifting material into the hopper, will help reduce dust levels and help prevent air from getting into the system.

    When adding bentonite, make sure it’s sent through the venturi and hopper at full throttle. You want to get the maximum implosion through the venturi to mix the product well. After enough bags of bentonite are added, keep product mixing through the venturi for approximately 10 minutes until it’s thoroughly broken up and hydrated.

    If you plan to add a polymer, you’ll need to wait until the bentonite is completely mixed (10 minutes). Adding a polymer too soon or out of sequence can cause the bentonite to ball up in the tank rendering it ineffective.

    The final step is to check the drilling fluid viscosity. If it's too thick, add additional water or thinners; if it is too thin, add more drilling fluid additives.

    A few housekeeping notes
    Mixing drilling fluid doesn’t have to be a messy job. Make sure you’re cleaning your mixing system’s hopper and venturi regularly to help prevent clogs. Also, make sure you’re washing your tank often. If there is polymer residue left in the tank when you go to mix up your next batch of drilling fluid, you could end up with small balled-up clumps of bentonite in your tank.


    Future articles of “Making sense of HDD drilling fluids” will cover the steps to calculate reamer pullback drill rates and explain the different types of drilling fluid additives available. For more information about drilling fluid mixing or the MUD hub, reach out to your local dealer, or visit Vermeer.com. 


  • « Back

    Creating an HDD Fluid Management Plan

    May/02/2018

    Is your company talking a lot about mud these days? You should be.

    With increasing regulations targeting the disposal of horizontal directional drilling (HDD) fluids and rising disposal costs, mud is becoming a major concern for the industry. Failure to plan can lead to unexpected expenses, missed opportunities or be the reason why your company isn’t awarded a particular project contract in the first place.

    Creating an HDD fluid management plan will help you more accurately estimate a project before work begins and keep your crews productive on the job. This provides peace-of-mind for you and your customers that your team understands the regulations pertaining to proper drilling fluid disposal.

    How much fluid do you need
    Your estimating process should include evaluating ground conditions at the jobsite, type of drilling additives you will need and the volume of fluid required for the project.

    Ground conditions dictate the drilling additives you’ll need and the amount of fluid required. In sand or cobble, you will likely only need a mixture of bentonite. In reactive clay,you will probably have to use a polymer additive. Keep in mind that harder rock usually requires more fluid per bore distance.

    Calculating the costs and the amount of additives and water you’ll need ahead of time will not only ensure you’re tracking your expenses on the project, but will also help you determine what equipment you need on the job.

    Adding in disposal costs
    Once you know how much fluid you'll need, the next thing to determine is how you plan to dispose of the spoils afterward.

    To begin, you must research all local regulations about disposing of drilling fluids. Today, many projects require HDD fluids to be disposed of at licensed facilities, and the costs associated with dumping can vary greatly. You will want to look into where these sites are located and estimate how much you’ll pay to use them.

    But don’t forget, the disposal costs aren’t your only expense. You also have to estimate the distance between the jobsite and disposal facility, as well as the fuel and labor costs involved in making the round-trip. These expenses are easy to overlook.

    Weighing your options
    After adding up your fluid and disposal costs, it’s time to evaluate equipment options that may be able to reduce your out-of-pocket expenditures. For projects that require large volumes of fluid, bringing in a reclaimer like the Vermeer R250C can help reduce the amount of fluid and additives used by removing solids and recycling fluids.

    Solidification systems like the Vermeer MUD Hub are another option to consider for projects that have high disposal fees. Solidifying used drilling fluids can give you more disposal options. Many drilling spoils will now be able to be disposed of at a regular landfill, used for ground cover or added to composting mixes. Also, since the waste is now a solid, it can be hauled in a dumpster or dump truck, which helps keep your vacs off the road and on the job.

    On the job
    There is a lot of upfront work involved with fluid management, but your plan should not stop there. On the job, you need to make sure the crew knows how to properly mix drilling fluids, understand how to measure fluid viscosity and use the proper amount of mud during the pilot bore, reaming and pullback. Mistakes made on the job can be as costly as not planning correctly.

    Documentation
    Finally, it’s important to document your disposal process and location for your customer. Many utility companies require fluid disposal documentation, but even if your customers do not, having a paper trail can help protect your business if someone has questions in the future.

    If you have questions about creating your own HDD fluid management plan, contact your local Vermeer dealer or visit Vermeer.com.

    ###

    Vermeer and the Vermeer logo are trademarks of Vermeer Manufacturing Company in the U.S. and/or other countries.

    © 2018 Vermeer Corporation. All Rights Reserved. 


  • « Back

    How to plan and mix your best HDD drilling fluid

    Apr/23/2018

    Operating a horizontal directional drill (HDD) is a bit of an art, but it takes science to be successful. Science is at the heart of the drilling fluid that runs through the drill string, helping to ensure downhole stability while cooling and lubricating tooling, as well as helping extract cuttings.

    Do you and your drilling crews understand the science involved with mixing drilling fluids?

    Why drilling fluid matters
    Whether you specialize in fiberoptics, gas, electrical, water or larger pipeline installations, using the right type and the right amount of drilling fluid needs to be part of the planning process. Drilling fluid additives provide critical filtration and suspension characteristics allowing for today’s longer and larger bores to be completed. Without these very important characteristics, you risk inadvertent returns (frac-outs), heaving ground surfaces and pullback failures.

    Drilling fluid additives The first step in your planning process is to understand the soil conditions you will be working in. The conditions tell you what type of additives you need. For example, in non-reactive clay, you will likely only need a mixture of bentonite, which produces needed cutting carrying capacity to flush the bore hole, and a lubricant to keep soil from sticking and bit balling to your tooling. However, when you’re working in reactive clay, sand or cobble, you will need a polymer additive.

    There are several types of polymer additives to choose from, each engineered to help you deal with specific soil conditions. PAC polymers are typically added to a bentonite mixture to help provide secondary filtration control (sands and cobbles). In formations with high concentrations of reactive clays, PHPA polymers are used in place of bentonite. PHPA polymers prevent clay from swelling by wrapping itself around the clay. A larger molecular weighted polymer is a good match for cobble and rocky conditions because it acts as a suspension aid and helps create a stable bore path and assists with extracting larger cuttings from the bore path.

    If you’re not sure about the soil conditions you’re going to be working in or if you have questions about which mixing additives you should be using, talk to your local HDD equipment dealer. They will be able to tell you what other contractors are using in the area. Also, be sure to follow the directions on the side of the additive bag or container to determine the correct amounts.

    Determining fluid amount needed
    Using the correct amount of drilling fluids on a bore is another critical consideration. The volume of fluid you should use depends on hole diameter and soil conditions. Vermeer recommends the following for HDD rigs up to 100,000 lb (444.8 kN). (Remember, the reamer is 1.5 times the size of your product up to 9” (22.9 cm). For product 10” (25.4 cm) and larger, the reamer is 1.3 times larger.)


    Next, you will need to calculate the soil safety factor by determining the ratio of fluid pumped to soil conditions.

    Armed with the information from these charts, as well as your drill rod length and your drill rig's pump output, you can now calculate the reamer pullback drill rate.

    For example, if you were going to use a Vermeer D20x22 S3 Navigator® horizontal directional drill to do a 300’ (91.4 m) bore in sandy clay and pull back a 4” (10.2 cm) gas line (pulling a 6” [15.2 cm] reamer), you should be using around 44 gal (166.6 L) of fluid per rod (1.47 gal/ft [18.26 L/min] x 10’ [3 m] x 3 divided by 25 gpm [94.6 L/min] = 1.76 min/rod x 25 gpm [94.6 L/min] = 44 gal [166.6 L]). Each rod is 10’ (3 m) long, so you will use 30 rods for the job, which means you’ll need approximately 1320 gal (4996.7 L) of fluid for the project.

    Performing this calculation before a project begins will help with the estimating and planning process.

    It’s common for crews to try to get by with less fluid than what is truly needed. This practice will cause drillers to outrun their mud. This means your fluid-to-soil ratio is too great and becomes too thick to pump out of the exit/entrance pit. The result of the pudding effect is an inadvertent return due to lack of flow underground. The ground will heave, product being installed will stretch, tooling can be damaged, and your tooling could potentially get stuck underground.

    Using too much fluid or product is wasteful and can create excess cost. However, don’t assume that inadvertent returns are always the result of using too little fluid. Inadvertent returns can also be caused by using the wrong type or amount of fluid additives.

    Mixing process
    Now it’s time to evaluate how your crew is mixing drilling fluids. This job is often assigned to a new person and they usually receive training from the person who did it before they were hired. If that’s your company’s process, you need to make sure both the teacher and student know what they are doing.

    First, start by checking the pH levels from your water source. Drilling fluid additives (bentonite and polymers) mix better with a pH level range between 8 and 9. Municipality water will typically measure around that range, but other water sources like ponds or wells usually fall below. Adding soda ash will help raise the pH levels and make your drilling fluid products go further.

    When you’re ready to mix your additives to the water, powders like bentonite must be added to the hopper and liquids are poured directly into the tank.

    Vermeer fluid mixing systems are equipped with a bag cutter next to the hopper. Use it to split the bag and then empty the whole bag into the hopper at once. Doing it this way, instead of cutting it with a knife and slowly sifting material into the hopper, will help prevent air from getting into the system, which can cause the tank to overflow and create a mess.

    When adding bentonite, make sure you’re sending it through the venturi and hopper at full throttle. You want to get the maximum implosion through the venturi the first time to mix the product as well as you can. After enough bags of bentonite are mixed through the venturi, keep the product mixing through the venturi for approximately 10 more minutes until it’s thoroughly broken up and hydrated.

    If you plan to add a polymer, you need to wait until the bentonite is entirely mixed, usually about 10 minutes. Adding a polymer too soon or out of sequence could cause the bentonite to ball up in the tank, rendering it ineffective. Always add a PAC polymer before a PHPA and dry polymers before liquid polymers.

    The final step is to check your viscosity using a marsh funnel and cup. You want a viscosity rate of 45-60 seconds for most drilling applications. If it's too thick, add additional water or thinners; if it is too thin, add more drilling additives.

    Understanding the science of mixing drilling fluids will help you take the art of drilling to the next level and help make your whole crew more productive. Learn more about this process by contacting your local Vermeer dealer or visiting Vermeer.com.

    ###

    Vermeer, the Vermeer logo and Navigator are trademarks of Vermeer Manufacturing Company in the U.S. and/or other countries.

    © 2018 Vermeer Corporation. All Rights Reserved. 


  • « Back

    Considerations for trenchless technologies versus open-cut methods

    Apr/12/2018

    The horizontal directional drilling (HDD) industry has come a long way since Vermeer introduced its first rig in 1991. The equipment, technology and drill crews have all become more sophisticated, which has helped expand the range of jobs drills can be used for. However, there is still a significant and growing market for open-cut methods, like trenching and plowing.

    According to Tod Michael, product manager for the trenchless core products at Vermeer Corporation, most underground construction projects have several factors that need to be considered when choosing between trenchless and open-cut installation methods. “There are the basic economics involved in the decision, like equipment, labor and restoration costs, but there are often more that contractors need to consider that impacts the decision,” he said, “such as ground conditions, the diameter of the product, grade requirements, underground and above-ground obstacles, as well as location.”

    Urban installation considerations
    In countries with more developed infrastructure, HDD is usually the preferred installation method for small-diameter utilities in urban and suburban locations. Michael said minimizing restoration, avoiding traffic disruptions and keeping property owners happy are a few of the reasons why HDD is used in populated areas. “Most of the time, boring a utility line is more cost-effective and takes less time because you go under roads and sidewalks, not through. Also, you do not have to contend with above-ground obstacles, like fences, roadways, sidewalks and driveways,” he added.

    There are regions of the world that still prefer to use open-cut methods in urban and suburban environments. Björn Van de Weghe, applications specialist for Vermeer EMEA (Europe, Middle East and Africa), explained unmarked underground utilities are a major concern in some cities. Van de Weghe said, “Trenchless methods are still used for crossing under roads and bridges, as well as over longer distances where no connections have to be made or crossed.”

    Rural installation considerations
    In rural areas, since there is often less restoration and obstacles to contend with, trenching and/or plowing is typically faster and more cost-effective for smaller diameter product.

    According to Jeff Utter, product manager at Vermeer Corporation, in more wide-open areas, contractors still need to consider which method makes the most economic sense. “Accounting for existing utilities, type of soil, the size of the product being installed and the required depth still need to be considered before choosing,” he explained. “It may be less expensive to use an open-cut method for shallow installations. However, for deeper installations or in rocky soil conditions, HDD may still be the best choice because less material has to be removed during the installation process.”

    Utter added that even if open-cut methods make the most sense for projects in rural areas, contractors should still consider using trenchless technology for passing under roadways, rivers and other above-ground obstacles.

    Large-diameter pipe considerations
    For pipeline projects including gas, oil or water, a combination of excavating and trenchless methods is typically used. “Over longer distances, open excavation will typically be more cost-effective than other installation methods, but the contractor should use a horizontal directional drill, auger boring machine or piercing tools to cross under roads, railways and rivers,” Michael said. “HDD should be considered for boring long distances and/or through cobble or rock. Auger boring machines are a great option for installing large-diameter steel casings short distances or if there is a limited space that would reduce the contractor’s setback distance. Piercing tools are very efficient for boring short distances and do not require a lot of setup time.”

    Vermeer Corporation and its subsidiary, McLaughlin Group, Inc. manufactures a wide range of trenchless and open-cut underground installation equipment, and the dealer network can provide expert advice to help contractors determine the most appropriate method for a particular project.

    For questions about trenchless and open-cut underground installation methods, contact your local Vermeer dealer or visit Vermeer.com.

    Vermeer is a trademark of Vermeer Manufacturing Company in the U.S. and/or other countries.

    © 2018 Vermeer Corporation. All Rights Reserved.