Two-Piece Plunger Lift Technology Research And Application

Two-piece plunger gas lift technology has been successfully applied in more than ten gas wells by ChevronTexaco company in Texas, the field test results show that single well dewatering volume and total dewatering volume of ten wells have increased significantly compared to previous foam dewatering. However, the technology has not been related to further theory research, just only to field application, domestic research on this technology has not been reported. To improve application level of two-piece plunger gas lift technology, according to the practical situation of low permeability, compaction and producing water gas reservoir in Daniudi Erduosi, two-piece plunger physical simulation flow experiments was conducted, FLUENT software was employed to simulate flow field of the plunger in the wellbore from the perspective of the optimization of the structure of two-piece plunger.(1) The Fluent software is used to numerical simulated for tubing internal flow field around the plunger in considerations of the specific parameters of wells in Daniudi gas field, gas channeling velocity of plunger with different groove width and groove depth distribution in flow field was analyzed, plunger outer wall structure of conforming to the parameters of Daniudi gas field Wells was designed, and theoretical basis for two-piece plunger component was provided for the field application.(2) the two-piece plunger gas lift visualization experiments shelf:tubing inner diameter Φ40mm with vertical height 19m designed, produced and installed. And this experiment shelf also provided convenience of correlational research for two-piece plunger gas lift wells or other gas dewatering wells.(3) Two-piece plunger physical simulation experiment is carried out, realized two-piece plunger with liquid running in experiment wellbore on condition of long-term none well shut in. Two-piece plunger gas lift experiment was respectively conducted in three different gas injected volume, and so did in each gas injected volume condition with three different liquid injected volume, and contrastive analyzing the impact of different fluid volume for parameters such as downhole pressure, wellhead pressure, plunger up and down time and plunger running cycle, obtained the relation between plunger up time and injected gas volume in different liquid volume.(4) Two-piece plunger components and wellhead limiter components were developed, and a series of two-piece plungers and wellhead limiters of different specifications were respectively designed according to different string structure in filed site. These two-piece plunger components were domestic initiative.(5) The developed two-piece plunger components and wellhead limiter components were used in Daniudi gas field. The application results to D61-17 well showed:the average daily water production and gas production were 0.92m3/d and 8778 m3/d,1.46m3/d and 10208m3/d respectively before and after two-piece plunger gas lift implemented, respectively increasing 58.7% and 16.3%, production function improved significantly. It is showed that this designed split plunger was in good behavior and succeed in field test. This is the first time to successfully apply two-piece plunger technology in field site.The research of this paper facilitated technical level and production efficiency of gas dewatering of domestic gas fields, filled the blank of domestic gas well production process without application of two-piece plunger gas lift technology, broaden gas dewatering technology.