Place of Application:                       Oil Field Damborice

Cleaning Technology:                     DIR-X solution for plugged wells

 

Stuck rod string and downhole pump in 2014

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Well Parameters 

Well depth 1700 m, reservoir temperature 48 °C, pump setting depth 1400 m, there was a problem with paraffin deposits.

The well was totally plugged with paraffin, the sucker rod string was stuck and “the bridle” was hung out (see photo below).  Standard cleaning method: hot oiling. In case of unsuccessful treatment pull the subsurface rod pump with rod string and tubing out of the hole, clean with steam from paraffin / asphaltene at the surface and clean the casing with a scraper. Standard cleaning method:  5-7 day workover / intervention.

 

Cleaning Process

Mixture quantity:  7.2 m³

Cleaning time: 3 hours

Process:  

• Pump DIR-X down the annulus to heat up the entire 1400 meters of well completion
• static fluid level 400 m
• pump DIR-X ( 7.2 m³) down the annulus
• chemical reaction had 6 time periods  – 24, 20, 16, 12, 6, and 2 minutes
• during pumping DIR-X (after 6 m³) pressure build up to 160 bars in the annulus
• after the reaction break (15 minutes) the pressure dropped and the remaining DIR-X was pumped down the annulus
• 10 m³ of oil was pumped down the annulus to wash spent DIR-X with melted paraffin out of the well

 

 

Result of Cleaning

The completely plugged well was cleaned with DIR-X solution in 4 hours and the well was put back into regular operation mode.

Figure 1 Hung out “bridle” and bent polished rod