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  • Reduced Corrosion: Case History

    13 April 2015
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    RAM’s ACC2000 Cellular Batch Controller Improves Corrosion Treatment Program.

    An East Texas producer was experiencing excessive corrosion problems at a rod-pumped well
    site. The well was previously being truck treated with corrosion inhibitor every 2-3 weeks. The
    well produces approximately 18 bpd oil and 25 bpd of water. Iron counts were typically over 100
    ppm indicating a higher than normal potential for corrosion. Rod corrosion was severe and the
    rod string required replacement or repair every 2-3 months.

    Well specs: 8200 feet vertical 3200 feet horizontal
    Casing – 7 5/8″
    Tubing – 2 7/8″
    Rod size – 100x 7/8″ Rods at the top.
    90x 3/4″ rods on the bottom.
    No sinker bars; uses 7/8″ rods
    Pump located in the vertical part of the well.
    Has a 1″ gas hanger pipe on the well pump that separates the gas to the casing.

    Treating rates PRIOR to the mini-batch unit – the corrosion inhibitor was pumped at the same rate
    (6 qts per day) continuously with an LMI chemical pump; but without the batches of flush fluid.
    A continuous “trickle flush” was initially attempted but it was not delivering near enough fluid to
    get the chemical downhole.

    Solution

    casehistory1after2A RAM ACC2000 remote cellular chemical pump controller was installed at the well site along with a standard diaphragm style chemical pump and an actuated flush valve. Figure 1 shows the piping of the flush loop on the well head PRIOR to installation of the automated system:
    (Image Left) – Flush loop piping PRIOR to installation of ACC2000)

    RAM_pump_SolutionAfter installation of the ACC2000 controller, the corrosion inhibitor was injected at ½ quart every 2 hours (every time the pump jack was activated by its timer); and the chemical injection was followed by a 1.25 minute flush of produced fluid, controlled by the actuated valve (see diagram below).

    This process continued 24 hours a day injecting 6 quarts of chemical on a daily basis.
    Essentially a “mini-truck treatment” occurred every 2 hours. The chemical injection followed by immediate flush insures that the inhibitor gets all the way down the casing to the formation and is produced back up the tubing with the normal action of the rod pump.

    The 12 flushes per day of well fluids (every 2 hrs) provided by the mini-batch unit was what made the huge difference in corrosion inhibitor effectiveness. It provided a larger flush volume but for a very short interval (about a minute) 12 times per day immediately after each 1/2 quart injection of chemical. We estimated the daily flush volume to be 1-2 barrels based on pressures & pipe size.

    Benefits

    Since the installation of the ACC2000 controller, there have been no rod failures in the past 2 years. Iron counts were reduced to less than 10. Total flush volume was reduced by using small controlled amounts throughout the day, this increased production efficiency.

    Uptime was increased by reduction of rod failures from corrosion.

    Most importantly, the entire system communicates remotely via the cellular network. Chemical injection rates and flush volumes can be monitored or modified. All information is recorded on the RAM data website and provides validation of chemical treatments. Chemical injection rates and flush times can be changed at any time via text message from an authorized cellular device. The complete RAM ACC2000 batch treatment system is shown in below.

    Casehistory1system

    CaseHistory_chart

    Cost Comparison:
    Before ACC2000:———— Rod Pull $7k (2-3 months)
    Tubing replacement ——– $16k
    Down time ——————— $32k/month (18bpd at $60)
    New rods———————– $25 – 50 each (40 this well)
    Truck treating —————– $200 x2 per month

    Total annual cost before: Approx… $65k
    (4 rod pulls, 1 month down time, chemical)

    After ACC2000: Cost of chemicals $675/month
    (1.5gpd at $15/gal)
    Cost of RAM equipment: $5k ( one time)

    Total annual cost after: Approx… $13k
    Estimated ANNUAL SAVING to Well Owner:
    Over $52k per year.

    Extra sales for chemical service company: $3.3k
    (increase of 68% sales)    2 years and still going.

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