Narrow Pressure Margin
The margin between pore pressure and fracture gradient can be as low as 0.2 in offshore wells, particularly deep water wells. Slim-hole and tight-annulus wells can create or compound the challenges of already narrow pressure margins. Formations with low fracture gradients can break down under the hydrostatic pressure of the drilling fluid or cement column and can result in lost circulation. The probability of maintaining circulation throughout cement placement operations can be higher when employing options such as lightweight systems and/or alternative placement methods.