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Natural Lift Systems Ltd. Well Candidate Procedures

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Preparing the Well

  1. NLS is pleased to provide a solution to your unwanted wellbore fluids. Your well needs to be specifically prepared to ensure its success. The well conditions will vary dependent on its age, type of fluids produced, corrosion, damage, etc. The degree of damage must be identified and corrected prior to a NLS Installation.
    Procedure
  2. Clean the casing running a casing scraper the entire length of the well. A solid scraper performs better than one with spring loaded blades. The inside walls of the casing must be clean and free of any and all build-up and accumulation of foreign material. If any tight spots are experienced, several passes must occur to ensure a consistent path for your casing plunger. Once casing is confirmed to have smooth continuous surface, proceed to the next step.
  3. Gauge or caliper the casing. It is essential to Identify the drift of the casing to ensure its size and continuity. If the well's casing does not meet size and drift specifications, the NLS casing plunger will not work as designed. NLS recommends a 3.96 inch Gauge Ring for 4 ½", 9.5 lb/ft casing.
  4. Swab the well. The well must be swabbed to eliminate current wellbore fluids and any foreign material. Once the well has been swabbed to the cellar, it should be allowed to produce for a short time to determine inflow. Swab the well again and identify amount of fluid for that time interval. This will provide a gauge on what liquids and foreign material are in the formation around the wellbore.
  5. Install a collar stop. NLS recommends a retrievable type of stop, set by Slickline service. The location of the collar stop MUST be installed above the targeted perforations, typically the first collar joint above the perforated zone. A Collar Log is helpful here. This will ensure a secure position for the NLS casing plunger to land. The typical fishing head dimension is 2.31 inches, which requires a standard 3 inch pulling tool.
  6. You may now want to shut the well in to control the liquid level.
  7. Procedures may vary dependent on well conditions.

Preparing the Wellhead

  1. Install a full-opening master valve on the casing. NLS recommends a Demco 4 ½ 8rd master valve, with a pressure rating that exceeds the actual bottom hole pressure. The master valve should be inspected fully open to ensure it has a consistent smooth surface with no extruded rubber or other irregularities that may compromise full drift.
  2. If the casing is flanged, or has tubing, kill the well and remove complete wellhead and install a 4 ½ 8rd Bell Nipple. Ensure the casing is cut clean, de-burred and filedsmooth before nipple is installed CONFIRM BELL NIPPLE IS ALIGNED WITH CASING (If the well is not 90 degrees vertical and the welder installs the nipple level, it will create a bend at surface potentially affecting plunger travel). If the nipple must be welded inside, ensure no material impedes the full drift of the casing.
  3. Install NLS Lubricator directly into casing master valve. All threads must be clean and properly coated with sealant. Ensure lubricator catch travels freely. Observe inside of lubricator is clean and full drift.
  4. Install unions, valves and flow lines. NLS recommends a one-way check valve in the flow line to inhibit pressure acting against the casing plunger
  5. PRESSURE TEST WELLHEAD. Close all surface valves, including flow line valve. Slowly open the casing master valve. Record pressure, check for leakage and correct if necessary.
  6. You are now ready to launch the NLS casing Plunger.

Operating the NLS Casing Plunger System

  1. Shut well in. Close the surface master valve and flow line valve. Open ½" valve on NLS Lubricator to bleed off pressure.
  2. Loosen hammer union on Lubricator and remove top section.
  3. Ensure Lubricator `Catch' is turned in.
  4. Install NLS Casing Plunger in Lubricator and re-attach top section. Tighten hammer union.
  5. Open flow line.
  6. Slowly open master valve fully and completely. If the is a large amount of production, the NLS Casing Plunger may rise up into 'Catch’. Let plunger remain there until initial pressure of well decreases.
  7. Once production stabilizes, open `Catch' and release NLS Casing Plunger.
  8. The Plunger will fall quickly until it reaches the fluid, then it should slowly sink until a sufficient amount of hydrostatic head is above the plunger to close the internal valve, stopping the descent of the NLS Casing Plunger.
  9. Once the internal valve in the NLS Casing Plunger is closed, the well is essentially shut-in below the tool. As the pressure increases below the tool, the NLS cups will flare, enhancing the seal with the casing, forcing the NLS Casing Plunger to rise, delivering the fluid to surface.
  10. Once the NLS Casing Plunger reaches the Lubricator, the fluid will be sent down the flow line, production will increase and the Plunger may stay at surface until the initial production `spike' stabilizes. The NLS Casing Plunger will then fall to repeat the cycle.
  11. If the operator wishes to retrieve the NLS Casing Plunger simply turn tile 'Catch' in on the NLS Lubricator and remove the tool on the next cycle. To retrieve the tool immediately, close flow line to build well pressure to a point above the closing pressure setting of the NLS Casing Plunger 'tricking' the internal valve to close. Then simply open the flow line, allowing the tool to rise to surface.
  12. If there are any questions or concerns not outlined above contact a NLS Representative at (403) 516 0613, (403) 519 9721 or at www.naturalliftsystems.com .