Paper: Lift Systems For Casing Production With Automation

THERE ARE CURRENTLY SEVERAL THOUSAND CASING PLUNGER LIFT SYSTEMS INSTALLED IN VARIOUS PARTS OF THE COUNTRY. THEY RANGE FROM VERY SUCCESSFUL TO FAILURES. THIS PAPER IS AN ATTEMPT TO EXPLAIN WHY THIS HAS BECOME THE CASE AND TO DELINIATE ISSUES OF WHERE TO APPLY THIS TECHNOLOGY. THE APPLICATION OF THIS TYPE OF artificial lift DESIGN MUST REQUIRE THE USE OF SOME PLANNING THAT IS NOT COMMON TO THE NORMAL TUBING PLUNGER LIFT DESIGNS. THERE ARE FEW SIMILARITIES BETWEEN THE TUBING PLUNGERS AND THEIR CONCEPT OF OPERATION AND WHAT OCCURS WITH THE CASING PLUNGER AND ITS OPERATIONAL CONCEPT. THE USE OF THE TUBING PLUNGER LIFT SYSTEM IS BASED IN FACT THAT THERE IS SUFFICIENT GAS FLOWING AT A HIGH RATE TO BRING THE COLUMN OF LIQUIDS ACCUMULATED IN THE TUBING STRING TO THE SURFACE. THE FLOW RATE IS AN ISSUE OF SUFFICIENT PRESSURE AND VOLUME TO ALLOW THIS TO CREATE A VELOCITY THAT CREATES A GAS/LIQUID SLUGGING. THE BALANCE OF THE VOLUME AND PRESSURE MUST BE ABLE TO DEVELOP THIS RATE AND OVERCOME THE HYDROSTATIC PRESSURE OF THE LIQUID COLUMN. THE INACCURATE BALANCE OF EITHER THE LQIUDI COLUMN OR THE VOLUME OF THE GAS OR THE PRESSURE OF THE GAS IN THE WELL OR IN THE VARIATION OF LINE PRESSURE CAN LEAD TO FAILURE. THE UNDERESTIMATING OF LIQUID OR AVAILABLE GAS OR FLUCTUATION OF LINE PRESSURE LEADS TO THE FLOW RATE BEING INSUFFICIENT OR THE FLOW BEGINNING BUT FAILING TO MAINTAIN THE TRAVEL TO HE SURFACE OF THE COLUMN AND PLUNGER. EXCESSIVE LIQUID OR DROPS IN WELL GAS VOLUME AND PRESSURE OR AN INCREASED LINE PRESSURE CAUSING PARTIAL LIQUID REMOVAL CAN BE TERMED PLUNGER "STALL". OPERATORS PURPOSELY, YET UNDERSTANDABLY, AVOID THIS INBALANCE THAT CAN LEAD TO NO FLOW OR NO LIQUID UNLOADING FROM THE WELL. THE ACTUAL REQUIREMENTS OF THE CYCLE ARE OVERESTIMATED BY FACTORING IN TOO MUCH GAS FOR THE ACCUMULATED LIQUID COLUMN AND THEN ASSURING THE LIQUIDS AND PLUNGER WILL ARRIVE.