In any waterflood project, every injection well should be equipped with its own water meter (flow meter). It is impossible to evaluate waterflood performance without individual well injection rate and cumulative injection data. Further, we have no better tool to evaluate the ongoing mechanical integrity of injection wells than careful monitoring of the injection rate (not to be confused with periodic mechanical integrity tests performed usually every five years). EPA has underestimated the value of individual well flow monitoring allowing the use of manifold monitoring, presumably based on bad information (see Water Meter Mistakes and Manifold Monitoring). At the very least, a few water meters should be rotated between wells to get a reasonable idea of individual well injection rates.Niagara Meters
Many different water meters have been used in the oilfields. The oldest meters were mostly of the nutating disc variety. The measuring element in such a flow meter consists of a disc mounted in a circular chamber. A partition or division plate that extends in from the chamber wall separates the inlet and outlet ports. Said plate fits in a notch in the disc and prevents rotation of the disc about its axis. The flow of liquid through the meter imparts a wobbling action to the disc, called nutation. This nutating action of the disc is such that the upper part of the shaft on which it is mounted travels in the shape of a cone with the apex pointed down. The lower face of the disc is always in contact with the bottom of the chamber on one side while the upper face of the disc is always in contact with the top of the chamber on the opposite side. Thus the chamber is divided into separate compartments of known volume, and as the flow of liquid actuates the disc, these compartments are successively filled and emptied, providing smooth continuous measurement. Connection between the disc shaft and a spindle dog transmits the motion to the register. Some models have an internal gear train and some have a magnetic coupling scheme that eliminates the need for a stuffing box.
The following is a collection of information on nutating disc water meters that have been historically used in the oil patch, followed by a brief discussion of other meter types:
See our Buffalo / Hersey One Inch Niagara Water Meter Service Notes.Five Pointer / 504 Meters
The Niagara water meter was very popular during the first big waterflood boom. Literally thousands of these meters were sold in Kentucky alone in the 1950's. The Niagara industrial meter dates back to 1859, and was originally manufactured by the Buffalo Meter Company of Buffalo, New York. Buffalo's domestic (household) version was called the American water meter, and some parts are interchangeable with the Niagara. The one inch Niagara meter uses the same measuring chamber as the old 5/8 inch American domestic meter. Hersey acquired the American and Niagara lines, and now the Niagara line belongs to Venture Measurement. One of the Niagara products is the good old Niagara nutating disc water meter, with accuracy of ±1.5% and repeatability of ±0.25%. Niagara water meter repair parts are available from Venture, but they are sky high!
The Niagara water meter was offered in a high pressure version good for 1,440 psi. The standard six bolt version was offered in iron with a cold water pressure rating of 300 psi, and in bronze with a cold water pressure rating of 200 psi. These pressure ratings were very conservative, and these meters have been routinely used at higher pressures (AnaLog Services, Inc. does not endorse or recommend exceeding manufacturer pressure ratings). Historically the repeatability of Niagara meters has always been stated as ±0.25%, but the accuracy has varied in company literature from 2% down to ±0.5%. Accuracy of Niagara meters was historically expressed as a percentage variation over the full recommended flow range, not as a percentage of full flow. It was therefore stated that the percentage variation is improved as actual operating flow range is reduced.
We have repaired hundreds of Niagaras, but it would be a fib to say we like to work on them. The best thing that can be said about them is that their measuring chambers look like tiny flying saucers. But those measuring chambers are more delicate than most, and they seldom survive a freeze without irreparable damage, even when the meter housing bottoms do not crack. The Niagara meter has a host of other problems, including a very short lived open gear train when used in oilfield service (there is a closed gear train that is a little better). We have a considerable stock of complete Niagara meters and repair parts, but we do not generally recommend Niagara meters.
See our 504 Water Meter Service Notes.Neptune Meters
The original "Five Pointer" water meter was a big heavy beast manufactured by Rockwell (do not drop this one on your foot). It dates back to at least the 1940s, and there was still a version of it in production into the 1960s. It is immediately recognizable by its large size, antique styling, and its eight bolt housing closure with 1-1/4" male pipe connections (the literature indicates there was a 1/2 inch and one inch version, but we have only seen the one size). We have a few of them in our collection of water meters, but have not repaired one in 15 years or more. There was also a 5,000 psi rated "Five Pointer", but it seems to use a different measuring chamber than either of the other two mentioned herein.
Around 1960, Rockwell introduced the Model 504, an excellent design they also referred to as a "Five Pointer". Rockwell's domestic (household) version was called the Arctic water meter, and some parts are interchangeable with the 504. The 504 can use the measuring chamber from the 5/8 inch Arctic domestic meter (there was a Tropic domestic meter also, but its measuring chamber has the wrong taper for the 504). By the early 1970s, Brooks, a division of Emerson Electric Company, had acquired the 504 meter from Rockwell. In late 1981, Brooks threatened to discontinue the 504, but reconsidered and raised the list price to $492.00. A few years later they kept their promise and ceased to produce the 504. Blancett, Inc. produced a 504 clone, their Model 500 water meter with a published accuracy of ±2%, listing for $545.00 in 2001.
The Rockwell / Brooks 504 and the Blancett 500 have a bronze case rated at 2,000 psi. The Rockwell / Brooks 504 has a Nickalloy measuring chamber and internal gear train. The Blancett 500 has a magnetic drive with no stuffing box, but it uses a less desirable plastic measuring chamber. Blancett also sold a retrofit kit to convert old 504 meters over to their magnetic drive mechanism and their plastic measuring chamber for $224.00 in 2001.
The 504 is a good meter for waterflood applications, and they are reasonably easy to service. They have decent freeze survivability. The metal measuring chambers are becoming difficult to find. We have a few complete 504 water meters in stock, and a fair stock of repair parts.
See our Neptune / Trident Meter Service Notes.Other Meters
Neptune Meter Company produced a high pressure water meter for the oil fields called the Well-Flood water meter. It was produced in a 5/8" x 3/4" and a 5/8" x 1" configuration rated at 2,000 psi, and in a larger one inch version rated at 1,000 psi. These meters were based on the famous Trident domestic (household) meter line, probably the most successful water meter design in the history of that industry. Tridents were made in two versions, the cast iron bottom (CIB) for areas subject to freezing, and the split-case version for the deep south and for basement installations. Nearly all the parts from the Trident can be used in the Neptune Well-Flood meter, but only the measuring chamber from the spit-case version will work due to the required chamber taper. These meters are workhorses, and a pleasure to work on. Unfortunately, not many are around. The Well-Flood meter is apparently no longer available, but the Trident line has lived on as the Type S (Green Seal) industrial meter.
We have had good luck using the old Trident, and the newer Triseal / Trident 8 (an upgrade of the Trident with magnetic coupling and no stuffing box) as shallow waterflood water meters. The CIB Trident and Triseal will easily function to 300 psi, and higher with special steel bottoms (though the inherent freeze protection of the CIB is lost). We use the CIB version outside because of its better freeze survivability, and the split-case version inside (in water plant buildings). Parts are still available to some extent. Though countless Tridents and Triseals have been scrapped for their brass, many are still in circulation, and quite a few are still in use by water utilities. We have been servicing Trident / Triseal meters for shallow waterflood service for over two decades. We have a considerable stock of complete Trident and Triseal meters and repair parts.
More recently, impeller and turbine meters have become commonplace for waterflood applications. Brooks sold many 792A and 793A vane meters prior to abandoning the market. Blancett's Model 900 impeller meter is still available and listed for $570.00 in 2001. Multi-jet water meters (long the standard in Europe) look promising, but have had little application in waterflooding.| Home | PBS Tech & Tips | AnaLog Tech & Tips | Service Tips | UIC |
Also see Injection Well Notes. Contact us if you have water meter questions or needs.