The wells have been stopped immediately after the descent of the technical casing. Accordingly, due to the lack of contact with mud rocks, wellbores due to downtime were not injured. In this way. at the beginning of restoration work, we had to restore only the minimum amount of drilling fluids and check their settings.
The first well (bottom 5191 m) was used clayless system BIOCAR-MT. Its high salinity possible to avoid problems with the enzymatic degradation of polysaccharide polymers and freezing at sufficiently low temperatures (less than -25°C).
PARAMETERS OF WASHING LIQUID "BIOCAR-MT" BEFORE WE BEGIN
- Density - 1.29 g/cm3;
- Funnel viscosity - 65 s;
- Gel - 72/82 dPa;
- PV - 25 mPa.s,
- YP - 201 dPa,
- Filtration loss - 4.5 cm3/30 min .;
- CTC - 0.12;
- total mineralization - 20%;
- KCl concentration - 6%;
- pH - 8.9.
On the other well (bottom 4082 m) was used polymer clay PIDM-2M system. As mineralization drilling fluid was low and there was a threat of freezing before stop drilling receptacles have been completely released. Drilling mud was transferred to other wells. Now, in the initial phase of drilling, there is a need to prepare the desired volume of washing liquid. After the restoration of circulation and initial processing of chemicals, we have achieved the following:
PARAMETERS OF WASHING LIQUID PIDM-2M BEFORE WE BEGIN
- density - 1,16-1,18 g/cm3;
- Funnel viscosity - 35-40 s;
- Gel- 15/30 dPa;
- PV - 12 mPa*s,
- YP - 30-40 DPA
- Filtration loss - 8-10 cm3/30 min .;
- CTC - 0.13;
- total mineralization - 11%;
- KCl concentration - 6%;
- pH - 10.5.
Currently mud stabilization parameters continues.
