Artificial Lift

Poor performance in rod pumping wells using downhole gas separation tools is not uncommon. The stems from a lack of evaluating well conditions before inserting a template gas separation tool which can handle liquid production and free gas in the system. Evaluating well conditions before designing the downhole gas separation tool while applying static & centrifugal principals have led to increased success for recent installations.

The conversion from ESP to rod pump is needed when well-inflow is insufficient to supply enough fluid to the ESP. However, achieving good pump performance in rod pump systems operating in depleted wells with high gas/oil ratio can be limited as well. Creating a multi-stage gas separator system which removes free gas before fluid entered the pump intake increases volumetric efficiency in depleted wells. The first stage is a slotted intake where gas can coalesce.

Production testing with digital electronic devices has been discussed for about 20 years amongst a small group.  The idea has been implemented a few times with uncertain results.  The uncertainty exists because the measurements were done with turbine meters which are themselves uncertain.  

Recent testing has been accomplished by gauging calibrated tanks.  We believe these measurements of liquid volumes can be viewed as perfect.  Measurement of gas is done with computerized orifice meters which are known to be accurate as long as the correct orifice size is used.

The last few years there has been quite a bit of advancement in the fiberglass sucker rods (FSR).  The published ratings across the fiberglass industry have increased over 20% with some manufactures going much higher.   What other benefits have come along with this increase?  Have there been any drawbacks?  This paper will discuss proper design criteria including importance of well specific criteria.

There is a growing awareness in the oilfield of the problems generated due to horizontal wells’ long lateral lengths, undulation fluid and gas trapping capabilities, inconsistent and aggressive unloading behaviors, and limitations on historically and widely applied separation methods.  Due to these impacting factors, horizontal rod pumped wells must address the resultant production behaviors as well as operational issues that can be worsened by poor application of old and non-optimal downhole separation and poor pump placement practices.

Alternative Measure of the Rate of Corrosion:  This paper discusses the various issues related to measuring the rate of corrosion in rod pumping systems and proposes and alternative measure.  The current conventional measure of corrosion considers the amount of water production and the amount of iron in the water.  The total amount of iron is then assumed to have degraded uniformly from the entire cross sectional area of the steel in the  

Producers can spend a significant amount of money repairing a sucker rod pump system without fully understanding the root cause of a failure. Incomplete, missing or incorrect data and over reliance on a supplier to “fix the problem” can be ineffective. Following “best practices” developed in other fields or generic “rules of thumb” may also lead to higher than expected failure rate especially in unconventional reservoirs.