The well has a horizontal section in the area of productive formations, target depth – 5245/6053 m.
This well should reveal the productive interval represented by fractured carbonate deposits for the first time at the field. This approach should significantly increase the drainage area and provide high productivity.
According to the project, the entire well, with the exception of Paleogene sediments and chalk containing horizons with drinking water, should be opened with utilization of OBM Witer II. To prevent contamination of water-bearing bed, when they are opened, specially designed environmentally friendly drilling mud, based on starch agent will be used.
For the first time, this technology was introduced in the previous well, and proved to be incredibly effective. Extremely high drilling speed was shown, as target depth of 5360 m was reached in 78 days. The industrial production, which exceeded the geological forecasts, was obtained 99 days after the start of drilling (100 WELLS UNDER THE FLAG OF GEOSYNTHESIS. The use of OBM WITER-II in the drilling of colloidal Mesozoic clays).
The use of OBM allows zones with incompatible drilling conditions in one interval such as deposits of plastic clays of the Jurassic and Triassic, and the deposits of brittle and fragmentary carbonite argillites. This reduces the drilling diameter and creates technical possibilities for the discovery of deep productive horizons from 6000 m and deeper. The Ø245 mm intermediate casing will cover the interval of the open hole 650 – 4000 m in this well, which is kind of a record.
We expect that the use of OBM Witer II in the range of the drift angle build up will achieve high stability of the wellbore walls at a lower density of drilling fluid, and reach high quality of the initial opening in this well.
INFORMATION ABOUT THE WELL:
CASING POLICY:
Surface casing Ø340 mm – 650 m;
Intermediate Сasing Ø245 mm – 4000 m;
Production casing Ø178 mm (vertical/along-hole) – 5175/5504 m;
Liner Ø127 mm (vertical/along-hole) – 5175/5504 – 5245/6053 m.
DRILLING FLUID TYPE:
Surface casing Ø340 mm – fresh-clay-drilling fluid;
Intermediate Сasing Ø245 mm – OBM «Witer-II»;
Production casing Ø178 mm – OBM «Witer-II»;
Liner Ø127 mm – OBM «Witer-II».
Well drilling term – 190 days.
Bottomhole temperature (5245 m) – 153 оС.
Drilling fluid density within the interval of 650-4000 m – 1180-1250 kg/m3;
Drilling fluid density within the interval of 4000-5504 m – 1700-1800 kg/m3;
Drilling fluid density within the interval of 5504-6053 m – 1150-1250 kg/m3.
