Niger Delta Petroleum Resources, Ltd.
Ogbelle Flow Station
Nigeria

Water Treatment Skid Operation

/ OPERATING PROCEDURES
REVISION: A
EFFECTIVE: September 09
PROCEDURE No: 001

1.0PURPOSE

1.1This operating procedure defines how tooperate the water treatment skid that Chemex supplied to Niger Delta Petroleum Resources (NDPR) for use at their Ogbelle Flow Station in Rivers State, Nigeria.

2.0 DESIGN INFORMATION

2.1The Chemex skid was designed based on a water sample provided by NDPR from the Ogbelle Flow Station site. The sample was analyzed and found to have a low pH (3.8), small amounts of metals (aluminum, barium, calcium, iron, magnesium, manganese, potassium, silica, sodium and zinc) and small amounts of other items (total dissolved solids, chloride and sulfate).

Chemex, in conjunction with a water treatment company (Water-Filter USA) designed a treatment system to raise the pH (using soda ash), provide chlorine (bleach) to handle any bacteria in the water, iron/magnesium to treat the water (remove rust, etc) and carbon to filter the water. The attached drawing 646-B18 shows the system.

The Chemex skid includes two (2) duplicate water treatment trains. NDPR will operate only one (1) train at a time to achieve 15 gallons per minute. The other train shall always be shutdown and the trains shall be alternately operated based on scheduled switchovers.

Chemex is supplying the water treatment skid and 2 years of consumables (pre-filters, soda ash and carbon filter media). NDPR is responsible for providing all items necessary to bring water to the skid and from the skid to the end users (including a storage tank). NDPR also is responsible for supplying the bleach locally (the system will use up to 40 gallons of bleach per month).

2.2The Chemex skid has been designed based on the following parameters:

  • Maximum flow rate: 12 to 15 gallons per minute
  • Minimum flow rate: 6 gallons per minute
  • Inlet Pressure: Minimum 25 psig required
  • Outlet Pressure: 1 to 2 psig less than the inlet pressure
  • The system is Pelican PC1000 with WF8 filter
  • Assumes 5,000 gallons per day water consumption
  • Requires 1 pound soda ash for every 2,667 gallons water
  • Requires 1 gallon bleach for every 4,000 gallons water
  • Carbon filter media to be changed as described below.

3.0 INSTALLATION

3.1The Chemex skid has been pre-fabricated to allow for easy installation. We recommend that the skid be maintained inside a covered area (such as a 20 foot container) with the supplies (soda ash, bleach, carbon sand & filters) kept in the same area and protected from the weather.

3.2Place the container in an easily accessible location with the water treatment skid and materials inside. Access to the skid should be limited to authorized personnel only.

3.3Connect the inlet water pipe (coming from the inlet water source such as NDPR’s water well) to the Chemex skid inlet connection.

Note: A minimum of 25 psig inlet pressure is required for proper operation of the skid.

3.4Connect the outlet water pipe (leading from the Chemex skid to NDPR’s storage tank) to the Chemex skid outlet connection.

Note: We recommend NDPR have an elevated storage tank capable of storing at least 3,000 gallons of water. NDPR will likely have surge demand exceeding the 15 gpm capacity of the water treatment skid. However, if a 3,000 gallon tank is used and filled at night, then the surge demand in the morning can be met. The tank will need an inlet control valve with tank level float that opens the valve when the tank water level is low and closes the valve when the tank is full.

3.5The Chemex skid has a single backflush drain pipe location. NDPR shall connect a pipe or hose to this drain point and extend the drain outside the container and to the desired discharge point.

Note: The water treatment skid will run a backflush every 1 to 2 days. This will discharge approximately 100 gallons (depending on the backflush run time). The water backflush discharge can be sent to a water holding/evaporation area or discharged from the site.

3.6Connect power wiring to the Chemex skid at a single point. The skid is pre-wired from that point to all the on-skid equipment and instruments.

Note: The pumps and flow switch on the skid are set up for 110 volt power only. A 2000 watt transformer is provided on the skid to allow NDPR to bring 220 volt power to the skid and convert it to 110 volt power. DO NOT hook up the skid components directly to 220 volt power or damage to the equipment will result.

3.7Test the skid electrical by placing each pump in the “momentary on” position (down position on the switch) to verify that each pump runs.

3.8Check that each iron tank electronic head has power to the electronics (it will be flashing 12:00 when power is established). Set the clock per the following:

  • Press the set clock button
  • Adjust the hours by pressing the ▼ or ▲ keys. AM or PM will change as the time runs along.
  • After the hours are set, press the “next” button to set the minutes.
  • Adjust the minutes by pressing the ▼ or ▲ keys and then press the “next” button to finish setting the time and return normal operation.

3.9Set the regeneration (regen) time on the iron tank electronic head by pressing the “next” and ▲ key simultaneously. Set the regen days as follows:

  • Press and hold for 3 seconds the “next” and ▲ key simultaneously. You will see the number “12”.
  • Push the “next” button. A number will show up. This number is the frequency for the regen cycle (days between regen).
  • Adjust the days between regeneration cycles by pressing the ▼ or ▲ keys.

Note: Due to the high anticipated daily usage (5000 gallons per day), we recommend a regeneration cycle occur every 2 days. If usage is less (say 3000 gallons per day) then set it for every 3 days. If usage is only 1000 gallons per day then set the regen for every 10 days.

  • Push the “next” button. The time of day will appear. Use the ▼ or ▲ keys to set the time of day when you want the regen to occur.

Note: The regen cycle should occur at night-time when the system is not likely to require water flow. We recommend 2 am or 3 am in the morning. The regen cycle will take around 30 minutes.

  • Push the “next” button 2 times to complete this task and return back to the original time setting.

Note: An immediate regeneration cycle can be started by pressing and holding the “Regen” button for at least 3 seconds.

3.10The pre-filter will arrive from Chemex with the internal filter coil already installed. No action is needed by NDPR to prepare this for startup.

3.11The iron tank will arrive from Chemex with the internal filter media already installed. No action is needed by NDPR to prepare this for startup.

3.12The carbon tank will arrive from Chemex with the internal carbon filter media (sand-like substance) already installed, soaked and flushed. No action is needed by NDPR to prepare this for startup.

4.0 OPERATION

4.1Once installation is complete as outlined above, the water treatment skid is ready for operation.

4.2Decide which of the two (2) trains will be run initially. Open the valves to allow for flow through the train. Close the valves on the other train. Close the valves for the water fill system to the chlorine and soda ash tanks on both trains.

4.3Close the selected train outlet valve temporarily prior to startup.

4.4Initial fill of the chlorine tank:for the selected train, fill approximately 12 gallons of clean water into the white chlorine tank. Then add 3 gallons of bleach and blend with a stick (good mixing not required).

Note: The Chemex skid has an automatic flow switch. When the flow switch senses that water is flowing through the system, it automatically turns on the chlorine and soda ash injection pumps.

4.5Initial fill of the soda ash tank:for the selected train, fill approximately 12 gallons of clean water into the blue soda ash tank. Then add 5 pounds of soda ash and blend well with the drill mixer.

Note: Measure 5 pounds using the measuring cup provided with the skid. Each level 1 cup scoop of soda ash is equal to 0.5 pounds. Therefore, if you need 5 pounds = 10 cups.

Note: Good mixing of the soda ash tank is required so that the soda ash is maintained in solution. Sludge build-up in the bottom of the tank must be avoided by proper mixing.

4.6Open the inlet valve to the Chemex skid and allow water to fill the system (but not flow through the system yet since the outlet valve is still closed).

4.7Open the outlet valve. Water should begin flowing through the system. This flow will trigger the flow switch and will start regular chlorine and soda ash chemical injection into the in-line piping.

4.8Water will flow through the Chemex water treatment skid until an external valve stops it. NDPR will provide a storage tank with an inlet control valve and tank level float that opens the valve when the tank water level is low and closes the valve when the tank is full. When the tank valve closes, this will stop flow through Chemex’s water treatment skid, which will automatically stop the chemical injection pumps.

Note: If desired, you can estimate the system water flow rate. Use two 5 gallon buckets and measure how many times you fill the buckets in an hour with the water coming from the outlet of the skid. For example, if you fill a 5 gallon bucket 120 times in an hour that equals 5 x 120 = 600 gallons. Divide by 60 minutes to get 10 gallons per minute.

4.9Setting the Chemical Injection Pump Injection Rate: It is important to set the rate of chemical injection properly to get the right pH adjustment and chlorine level in the water. Follow these procedures to set the rates:

  • You will need to manually adjust the chemical injection pumps by trial and error to get the proper pump rate (%) on the pump dial. The dial can be adjusted between 5 and 100%.
  • Set the dial for 50% initially. The pumps will begin injecting bleach and soda ash into the system.
  • Take a 1 liter water sample at the sample port provided at the inlet to the iron tank head.
  • Use the pH test kit provided and check the pH level. The pH level should be between 6.0 and 8.0. If the level is low, increase the soda ash injection rate (go up from 50% on the dial). If the pH is high, decrease the soda ash injection rate (go down from 50% on the dial). Wait a few minutes and re-test the water and continue adjusting the dial until the pH is in the proper range.
  • Use the chlorine test kit provided and check the chlorine level. The chlorine level should be close to 1.5 parts per million (ppm). If the level is low, increase the bleach injection rate (go up from 50% on the dial). If the chlorine level is high, decrease the bleach injection rate (go down from 50% on the dial). Wait a few minutes and re-test the water and continue adjusting the dial until the chlorine is 1.5 ppm.
  • After making the initial dial settings on the chemical injection pumps, NDPR shall monitor how quickly the 15 gallon chemical injection tanks are emptied to determine how often they should be monitored and re-filled.

4.9After 7 days of continuous operation, we recommend that the operator switch from one train to the other train (i.e. every Monday the trains are switch so both get equal usage). Keep switching the trains one time each week for the life of the system.

4.10After 24 hours of flushing, the system should be ready for use as potable water. We recommend a sample be taken after at least 24 hours use and sent to the USA so Chemex can test it and verify the condition of the water.

5.0 MAINTENANCE

5.1Initially the operator shall take a water sample daily from the sample point at the iron tank head. Test the sample for pH and chlorine using the Chemex-supplied pH strips and chlorine kits. After 1 month of operation and fine-tuning, check the pH and chlorine weekly instead of daily.

5.2An operator will need to check the Chemex water treatment skid at least once per day. The operator shall daily verify that that there are no leaks in the piping, that the chlorine and soda ash chemical tanks are at least 1/3 full (at least 5 gallons in the each tank) and that each chemical pump is operational and regularly injecting chemicals in the pipe when water is flowing.

5.3Chlorine tank consumption will be 1 gallon of bleach per 4,000 gallons of water processed. If the chlorine tank is less than 1/3 full (below the 5 gallon mark on the tank), then the tank shall be filled up. To fill up the tank, use the water fill piping, open the valve and watch the tank level compared to the marks on the tank.

Note: To fill up the chlorine tank, use the following guidelines:

  • If tank is at 10 gallons full, add 4 gallons water and 1 gallon bleach
  • If tank is at 5 gallons full, add 8 gallons water and 2 gallons bleach
  • If tank is empty, add 12 gallons water and 3 gallons bleach

5.4Soda ash consumption will be 1 pound of soda ash per 2,667 gallons of water processed. If the soda ash tank is less than 1/3 full (below the 5 gallon mark on the tank), then the tank shall be filled up. To fill up the tank, use the water fill piping, open the valve and watch the tank level compared to the marks on the tank.

Note: To fill up the soda ash tank, use the following guidelines:

  • If tank is at 10 gallons full, add 4 gallons water and 1.75 pounds (3½ cups) soda ash
  • If tank is at 5 gallons full, add 8 gallons water and 3.5 pounds (7 cups) soda ash
  • If tank is empty, add 12 gallons water and 5 pounds (10 cups) soda ash
  • After soda ash has been added to the tank, mix the tank well until all the soda ash is in solution using the hand drill and mixer bit.

5.5The operator shall verify that the iron tank electronic head has power and that the time is correct. If the time is incorrect, then a power outage likely occurred. The operator will need to re-program the time and regen cycle on the head.

5.6The operator shall change the inlet pre-filter 1 time per month. Chemex has shipped 48 spare filters. This will equal 2 years of changes (1 per month per train x 2 trains). Change out by following the instructions on page 18 of the Pelican WF4/WF8 Owner’s Manual.

5.7The iron tank does not require filter media change out until after 10 years operation. When 10 years have passed, then contact Chemex or Water Filter USA for new materials and the procedure for tank filter media change out.

5.8The carbon tank has a small amount of carbon filter media material inside it (not completely full). The carbon is good for approximately 1,000,000 gallons of throughput. The exact gallons of throughput are not know at any given time but if 5,000 gallons per day are used and train 1 and 2 are alternated weekly, then change out the carbon after 12 months. At 3000 gallons per day, change out the carbon after 20 months.

  • To replace the carbon media, change to the other treatment train and shut the valves on the train that will have the carbon media replaced.
  • Release the tank from its plumbing on top using quick release knobs.
  • Unscrew the head from the tank and pull the riser tube out of the tank.
  • Remove the carbon tank from its stand, turn it upside down and pour the old media out of the tank. There should only be a small amount of media (the tank is not anywhere near full of media).
  • It may be necessary to use a water hose to wash the wet media off the insides of tank.
  • Set the riser tube back into place inside the tank. The riser tube will rest in the center of the bottom of the tank.Cover the top of the riser tube with a piece of tape.
  • Pour the new white gravel (one bag, supplied by Chemex) into the tank with the funnel provided
  • Pour the new carbon filter media into the tank with the funnel provided.
  • Remove the tape from the top of the riser
  • Take the tank head and place it over the riser tube now inside the tank and push down to screw the head back onto the tank.
  • Follow the 48 hour soak and flushing instructions listed in page 10 of the Pelican WF4/WF8 Owner’s Manual.
  • Put train 1 back into service.
  • Follow this same procedure on train 2.

5.9For questions on operating the chemical injection pumps, refer to the Chem Tech Operations Manual. For questions on the Iron Tank electronic head, refer to the C-Series manual. For questions on the entire system, refer to the Pelican WF4/WF8 Owner’s Manual.

Date Printed: October 24, 2018Page 1 of 7