We’ve learned so many topics regarding wait and weight well control method and I would like to share what advantages and disadvantages of wait and weight method are.
Advantages of Wait and Weight Method
• When compared to driller’s method, the wait and weight will generate lower pressure at casing shoe while circulating.
• It will generate the lowest pressure on surface equipment.
• It requires less circulation than driller’s method therefore time of equipment exposed to pressure is less.
Disadvantages of Wait and Weight Method
• Complex calculation is required for deviated wells.
• Sufficient weighting material is required to make kill weight mud. If you don’t have enough weighting agent, it would be better to circulate kick out and shut the well in.
• Gas migration in the mud can cause confusion while the kill weight mud is being mixed because bottom pressure, casing and drill pipe pressure will increase.
• Take time to wait for mixing kill weight mud. It may not good idea for waiting if you have weak formations because gas migration will cause increase in bottom hole pressure. You may end up with loss circulation.
Reference book: Well Control Books