Innovations

Reverse Circulation Blade Underreamer

Problem: LaFramboise Drilling of Thompson, Connecticut, needed to under ream with reverse circulation through an 18" casing to open up to 36" in sand and gravel. The hole needed to open up at depths from 375' to 450' for the Suffolk County Water Authority in South Hampton, Connecticut. They were drilling with a Failing F-10 machine with a Jed A Eductor system for reverse circulation. Their dilemma was that a reliable Underreamer designed for Reverse Circulation did not exist.

Solution: Mills Machine of Shawnee, Oklahoma rose to the occasion, and designed a reverse circulation, two blade underreamer to operate through the 18" casing and open up to 36". The flange mount bit used a 17 7/8" two blade pilot bit and pivoting arms on the body to open up beyond the casing. The drilling operation took 12 hours from set up to tear down.

LaFramboise Drilling was so impressed that they ordered a second, smaller underreamer to address another very challenging application. The New York City Department of Parks needed to install four 12" wells at their municipal golf courses to produce at least 800 gpm. The plan called for going through an existing 12" casing and open up to 24" from 150' to 400' in gravel. Their new 11 ×" to 24" Reverse Circulation Underreamer did the trick and as a bonus the actual output was 2000 gallons per minute and up.

Hoist Plug Knocker Wheel

Problem: There are basically two different types of Hoist Plugs available to handle rotary drill rod and related tooling. The standard screw in hoist plug and the split thread fast plug. The split thread fast plug is popular with many drillers because it is a time saver. You just insert the tapered split thread connection into the drill rod and the taper works like Chinese handcuffs, the tighter you pull it the tighter it grips. But, it is only available in a few thread sizes and many drillers are afraid of the fast plug releasing the drill rod prematurely if it is banged around in the tower. The standard screw-in hoist plug is favored by most drillers because it provides a regular thread make-up just like their drill rod connections but, it is a lot slower to use and it's hard to screw in and out with greasy hands or gloves.

Solution: Mills Machine manufactures a cross between the fast plug and the standard screw in plug. The Knocker Wheel Hoist Plug provides the safety and reliability of the standard hoist plug and the speed of the fast plug. You merely screw the plug into your drill rod and bump it to the right to tighten it and when your finished bump it to the left and spin it out. The Knocker Wheel Hoist Plug can be manufactured to meet your individual thread requirements.

Dogleg Straighter

McCall Brothers Inc. of Charlotte, N.C. has been involved with groundwater development since 1938. The company builds water treatment and waste treatment facilities, drills all types of wells and installs pumps and controls for water production.

Problem: They were drilling a 28" hole with a drag type reamer to a projected depth of 540 feet. At 270 feet they hit hard blue clay and then hard rock. What they didn't know at the time was that even with proper stabilization the reamer pushed off, resulting in a crooked hole. The drillers found the "dogleg" when they tried to set their 20" casing, it just wouldn't go past the 270' mark. To straighten the bore, they even tried drilling a 29" hole, but the bit just followed the same hole, and the casing still wouldn't go.

Solution: Working with Mills Machine Co. of Shawnee, Oklahoma, a special dogleg straightening tool was developed based on a process used in the oil field where a two cone roller bit is used to straighten a crooked hole. Mills Machine designed a special 28 7/8" rectangular roller bit. The concept was to lower the bit down to the deviation point and slowly rotate through the rock ledge causing the dogleg. The combination roller cone and claw bit tool was inserted with a 40 foot stabilizer and they were able to drill a straight hole to the 540' level desired and meet the needs of Craven County Well #5.