Place of Application:                      Oil Field Damborice, Oil Field Borkovany

Cleaning Technology:                    Downhole equipment preventive cleaning (rod string and tubing) with DIR-X (during production) – usually 2-3 wells in a row

 

10 – 15 Wells are preventively cleaned twice / three times per year from 2015 to date

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Well Parameters

Wells: depth 1 700 – 2 200 m, reservoir temperature 48 – 55°C, pump setting depths 1 400 – 1 900 m, there were a problem with paraffin deposits

Standard cleaning method: once a month hot oiling (with 30 – 38 m³ of hot oil). Usual time between the failures was 12 – 18 months. Workover / intervention required (4 – 5 day): pull the rod pump with rod string and tubing out of the hole, cleaning with steam from paraffin at the surface, casing cleaning with the scraper.

 

Cleaning Process – Heating up the downhole completion during production

Mixture quantity: 4.8 – 6 m³ per well

Cleaning time: 2 hours per well

 

Process:  

• each well is connected to the central pipe line system (gathering station)
• pump DIR-X (4.8 – 6 m³) down the annulus
• the chemical reaction is divided into four / five time periods (depends on the expected paraffin deposits depth)
• after the reaction brake (5 – 10 minutes), pump 2 – 10 m³ of oil down the annulus to wash out the spent DIR-X with melted paraffin deposits out of the well
• oil pumping did not have to be interrupted during the cleaning process with DIR-X solution

 

Identical procedure was applied for each well.

 

Result of Cleaning

Well cleaning with DIR-X is currently performed twice / three times per year. The run life – interval between failures – was increased from 12- 18 months to 42 – 48 months.

DIR-X solution is preferring cleaning method for wells with paraffin issue.

 

Figure 1 Three wells cleaning in a row – temperature profile at the wellhead

 

Figure 2 Three wells cleaning in a row – pump truck