METHOD FOR STEP-BY-STEP WELL GROUTING Russian patent published in 1995 - IPC

FIELD: drilling. SUBSTANCE: grouting slurry is of the first stage is pumped into casing string. The slurry is forced into the well throw string boot. Lateral cementing hole is opened in the string. Extra portion of grouting slurry is washed out of the well. This is ensured by pumping service water into beyond tube space. The volume of the water is specified. This volume exceeds half of that for service water/grouting slurry mixture. Fluid flow at well outlet is throttled after service water has been pumped in. On completion washing extra portion of grouting slurry out additional portion of service water is pumped in. This water is pumped in beyond tube space. This is carried out through lateral cementing holes. Required volume of service water is pumped in as additional portion. This volume exceeds that of mixture of this water and mud in beyond tube space. Throttling fluid flow at the inlet is stopped until additional portion of service water starts to be pumped in. Throttling is stopped until complete pressure drop at the inlet. Beyond tube space at the inlet is sealed after completion pumping in additional portion of service water. Excessive pressure is built in the string. This is ensured when fluid is pumped in the string from the inlet. Pressure is being maintained until grouting slurry of the first stage has consolidated. EFFECT: preventing oil/gas/water ejection in the process of thickening and consolidation of grouting slurry of the first stage.