Recently, JSC Ukrgasvydobuvannya has completed drilling the operation well in the Gadyach field in the frameworks of the pilot project with M-I SWACO, Schlumberger Company, namely - tail interval drilling using the oil-based mud VERSACLEAN.

Thus, after the development of the mentioned well, the daily yield made 86 ths.cub.m of blue flame natural gas that exceeded the expected result by 30%. In the frameworks of the project, it is currently planned to drill one more inclined-oriented well in the Gadyach field.

Mykhailo Paduchak, the Director for Drilling, quoted: "For UGV, this is the first successful experience of using the oil-based muds that make it possible to increase the production performance in the empty fields with low formation pressures due to primary qualitative development of pay formations. The success was due to new advanced approaches that are actively implemented by the Drilling Department employees and well designer, UkrNDIGas branch. Given the obtained positive result, the Company considers the possibility of using this drill mud system in more than ten wells during the pay formations drilling.

Among the main advantages of using the oil-based muds that are common in the world-drilling practice are the following:

• • increased production performance due to the reduced pollution of pay formations;
• • accident reduction during well-construction;
• • reduced well expenditures due to re-using 60% of the solution that is necessary for the drilling of one well.

It is worth noting that environmental protection is much focused when using the oil-based muds. That is why to observe the ecological standards, the M-I SWACO Verty-G special equipment complex was installed at the well for cleaning and further disposal of solid phase and re-use of the restored drill mud.