The Driller
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • CLASSIFIEDS
  • EQUIPMENT
  • SAFETY
  • VIDEOS
  • EDUCATION
  • SOURCEBOOK
  • EVENTS
  • SUBMIT
  • ABOUT
  • SIGN UP
cart
facebook twitter linkedin youtube
  • NEWS
  • Water
  • Geothermal
  • Construction
  • Environmental
  • Mining
  • All Industry News
  • EQUIPMENT
  • Rigs & Heavy Equipment
  • Consumables
  • Pumps
  • Featured Products
  • VIDEOS
  • Newscast
  • Drill Talks
  • Ask Brock
  • Emerging Drillers
  • EDUCATION
  • Drilling Business Insights
  • Reference Desk
  • Sponsored Insights
  • EVENTS
  • Conferences & Demo Days
  • Newscast LIVE
  • SUBMIT
  • Drillers @Work
  • ABOUT
  • Contact
  • Advertise
The Driller
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
The Driller
  • NEWS
    • Water
    • Geothermal
    • Construction
    • Environmental
    • Mining
    • All Industry News
  • CLASSIFIEDS
  • EQUIPMENT
    • Rigs & Heavy Equipment
    • Consumables
    • Pumps
    • Featured Products
  • SAFETY
  • VIDEOS
    • Newscast
    • Drill Talks
    • Ask Brock
    • Emerging Drillers
  • EDUCATION
    • Drilling Business Insights
    • Reference Desk
    • Sponsored Insights
  • SOURCEBOOK
  • EVENTS
    • Conferences & Demo Days
    • Newscast LIVE
  • SUBMIT
    • Drillers @Work
  • ABOUT
    • Contact
    • Advertise
  • SIGN UP

Bore Planning

By Jim Piasecki
March 8, 2001
Take a look at forumlas that can help drillers avoid out running their drillling fluids.

Over the past few years there have been numerous articles on bore planning. Most of these articles focused on a major problem in the horizontal directional drilling (HDD) industry: OUT RUNNING OUR DRILLING FLUIDS. Let's look again at the formulas that help avoid this problem and address other problems not associated with the fluids, which are causing most of the contractors' unwanted problems.

To understand drilling fluid requirements, we need to establish parameters of the bore: length of bore, reamer type and size, and soil conditions. Always keep in mind there is no universal soil type; therefore, there is no one universal drilling fluid, reamer, or set time to do a successful bore. Look at every new bore as if it was your first, regardless of your experience or how successful you have been in the area in the past.

To calculate your fluid requirements, you need to determine amount of soil to be removed to have an adequate passageway for the product pipe being pulled in. To do this, we use the following formula.

  • Diameter of reamer squared divided by 24.5 = volume (gallons/linear foot)

Example: 12" reamer
12 x 12 = 144 / 24.5 = 5.88 gal. drilling fluid / linear ft. soil should be removed.

To remove the soil and have flowable slurry in sands or dirt-like soil, you need to apply a minimum of two times the fluid-to-soil ratio to every foot of soil to be removed. This allows for fluid loss and absorption of fluids into soil being removed. In clays and harder, more reactive soils, you should apply three to five times the fluid-to-soil ratio to keep the drilled slurry flowing. If the soil is not removed, the product pipe has little or no chance of being pulled through.

Using this practice on a 500 ft. backream in a sandy or dirt-like soil, we can plan to use about 5880 gallons of drilling fluid (2 x 5.88 gal./ft. = 11.76 x 500 ft. = 5880 gal.). If we were in a clay or more reactive soil requiring use of polymers and additives, we would need to use three to five times more fluid to keep the soils mixed in the slurry. That would require us to use 8800 to 14,700 gallons of drilling fluid. These reactive soils can greatly increase the time and expense required to complete the bore.

Time required to do the bore is based on hardness of soil conditions, size of rig used, and how long it takes for the reamer and fluid to mix the soil into the slurry. In most cases, the power of today's machines makes it very easy to pull back too fast, not allowing enough fluid to be pumped down hole. This ultimately causes stuck drill pipe, stuck product pipe, and the ever-dreaded frac-out or speed bump. Pull-back time should be based on output of your pump: the faster you can pump drilling fluid in the hole, the faster your pull-back time.

For example, using a 12" reamer on the 500 ft. bore, we calculated we will need 5880 gallons of fluid (for sands or dirt). If we divide that volume by output of our pump, which in this case is 40 GPM, it will take three to six hours to do the pull-back. This does not take into consideration down time, which leads me into what I perceive as one of our biggest problems today: NOT ALLOWING ENOUGH TIME TO DO THE JOB RIGHT.

Time. We never allow enough to do the job right the first time, but always seem to spend a lot of it redoing the project, which costs us money. If time is money, why are we not using it effectively?

Most projects have time restrictions, which usually allow us to work between 7a.m. and 5p.m., or about 10 hours a day. Of these 10 hours, only about seven are productive hours, as in most jobs we need the first hour to get ready and the last hour to clean up/reset barricades, and we shut down for an hour lunch. How you use these seven hours of production is critical to a successful bore. Using the example bore mentioned-500 ft. 12" without a pre-ream-we estimated three to six hours to do the boring. That is machine time only, not including breaking rods, changing racks, mixing fluids, getting water, vac and hauling time, visiting with inspectors, and talking with your girlfriends on the cell phone. The biggest problem with time management on the job is vac and hauling time. Very few contractors allow for time it takes to dispose of spoils or provide enough vacs or large enough vacs to do the job efficiently. This problem, along with inadequate mixing systems and water sources, is adding six to 10 hours to the job and, in more cases than we want to admit, causing us to lose the bore. Because of added time for vac and hauling, we are not allowing needed drilling time to remove and mix up the soils.

Looking at vac time alone, say we have a 750 gal. vac unit. Using the example bore mentioned above, we need to remove between 8800 and 14,700 gallons of material. (Drilling fluid required + soil removed from bore path). This will require filling and dumping our vac 12 to 22 times. As I have seen on most jobs, it can take 30 to 60 minutes to dump a load. This can add six to 22 hours of unproductive time to the job. We would need to seriously look into having a second or larger vac available. A larger vac alone will not save money (due to down-time) but will decrease number of trips to the dumpsite. Mud mixing and having a source of water available also calculates into lost production when not properly planned.

Also, make sure you have the product pipe on site and ready to pull when needed. Check your inserts and pulling cables for wear. Don't stop pulling back product pipe once you start, and avoid unnecessary cell phone calls when work needs to be done. I have seen crews lose one to two hours of production time a day because the operator or key person was on the phone, unnecessarily in a lot of cases. Remember-time is money; use it as effectively and efficiently as possible.

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Jim Piasecki is a regular contributor to The Driller.

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • geotechnical drilling rig

    6 Onsite Phrases Environmental Drillers Hate

    Here are six phrases that highlight common frustrations...
    The Underground Network
    By: Jeff Garby
  • Wayne Nash

    Pipe Stuck? Common Causes and Solutions for Drillers

    If you have drilled for any length of time, sooner or...
    World According to Wayne
    By: Wayne Nash
  • submersible pumps, water well pumps

    Selecting and Sizing Submersible Pump Cable

    This article helps pump installers and servicers decide...
    Markets
    By: Bob Pelikan
You must login or register in order to post a comment.

Report Abusive Comment

Subscribe For Free!
  • eNewsletters
  • Online Registration
  • Subscription Customer Service
  • Manage My Preferences

The Driller Newscast: Coiled Tubing Drilling and the Future of Geothermal

The Driller Newscast: Coiled Tubing Drilling and the Future of Geothermal

The Driller Newscast, Episode 147: Global Geothermal Collaboration at NY-GEO 2025

The Driller Newscast, Episode 147: Global Geothermal Collaboration at NY-GEO 2025

The Driller Newscast: 21st Century Drillers | Part 1 DEMAND

The Driller Newscast: 21st Century Drillers | Part 1 DEMAND

The Driller Newscast: New York Geo Talks 2025 Conference with Hands-on Driller Education

The Driller Newscast: New York Geo Talks 2025 Conference with Hands-on Driller Education

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the The Driller audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of The Driller or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • demo of a DM450 drilling rig during a customer factory visit
    Sponsored byGeoprobe

    Built for You: Smarter Drill Rigs, Stronger Support, Bigger Opportunities

Popular Stories

MainPhotoTwoBrothers.jpg

Two Brothers' Journey Through the Drilling Industry

AI and Drought Concerns

AI’s Growing Thirst for Water and Power

demo of a DM450 drilling rig during a customer factory visit

Built for You: Smarter Drill Rigs, Stronger Support, Bigger Opportunities

The Driller Classifieds

COMPRESSORS

EAST WEST MACHINERY & DRILLING IS BUYING AND SELLING AIR COMPRESSORS, AIR BOOSTERS, AIR ENDS & PARTS
Company: East West Machinery

DRILL RIGS

LOOKING FOR LATE MODEL TOPHEADS & DRILLTECH D25'S
Company: Spikes’s Rig Sales

DRILL RIG PARTS

MEETING DRILLERS NEEDS AROUND THE WORLD
Company: East West Machinery

ELEVATORS

SEMCO INC. PIPE ELEVATORS
Company: Semco Inc.

GROUTERS

GROUTING EQUIPMENT - GROUT PUMPS & GROUT HOSE REELS
Company: Geo-Loop Inc.

PUMP HOISTS

SEMCO INC. - BASIC PUMP HOISTS
Company: Semco Inc.

WELL PACKERS

LANSAS PRODUCTS - INFLATABLE WELL PACKERS
Company: Vanderlans Lansas Products

WELL SCREENS

WELL SCREENS & SLOTTED PIPE
Company: Alloy Screen Works

Products

Water Quality Engineering: Physical / Chemical Treatment Processes

Water Quality Engineering: Physical / Chemical Treatment Processes

By carefully explaining both the underlying theory and the underlying mathematics, this text enables readers to fully grasp the fundamentals of physical and chemical treatment processes for water and wastewater.

See More Products

Subscribe to The Driller Newscast

Related Articles

  • HDD Project Planning Tool

    See More
  • HDD Bore through a Very Steep Slope

    See More
  • Water Supply Planning: Is the Industry Involved?

    See More

Related Products

See More Products
  • 9780071762458.jpg

    Trenchless Technology: Planning, Equipment, and Methods, 1st Edition

  • deepwater.jpg

    Deepwater Drilling 1st Edition

  • fundamentals.jpg

    Fundamentals of Sustainable Drilling Engineering

See More Products

Related Directories

  • Deep Foundations Institute (DFI)

    Deep Foundations Institute is an international association of contractors, engineers, manufacturers, suppliers, academics and owners in the deep foundations industry. Our multidisciplinary membership creates a consensus voice and a common vision for continual improvement in the planning, design and construction of deep foundations, ground improvement and support of excavation.
×

Dig deeper into the drilling and water supply industry!

Build your knowledge with The Driller, covering the people, equipment and technologies across drilling markets.

SIGN UP NOW
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
    • Classifieds
  • SIGN UP TODAY
    • Create Account
    • eNewsletters
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing

The Driller
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
The Driller
  • NEWS
    • Water
    • Geothermal
    • Construction
    • Environmental
    • Mining
    • All Industry News
  • CLASSIFIEDS
  • EQUIPMENT
    • Rigs & Heavy Equipment
    • Consumables
    • Pumps
    • Featured Products
  • SAFETY
  • VIDEOS
    • Newscast
    • Drill Talks
    • Ask Brock
    • Emerging Drillers
  • EDUCATION
    • Drilling Business Insights
    • Reference Desk
    • Sponsored Insights
  • SOURCEBOOK
  • EVENTS
    • Conferences & Demo Days
    • Newscast LIVE
  • SUBMIT
    • Drillers @Work
  • ABOUT
    • Contact
    • Advertise
  • SIGN UP