Hole cleaning – reduce time in drilling operations

Situation

A horizontal drilling operation might result in poor hole cleaning. To overcome the hole cleaning issue, traditional procedure is to circulate mud with no drilling progression (ROP=0). This results in additional time spent in drilling operation.

Cost calculation

With a pump flow of approx. 1 m/s on depth 3600m, it will take one hour to circulate the complete well, and 4 circulations is necessary to clean the hole, resulting in 4 hours circulation time, with no drilling progression.

This circulation procedure needs to be repeated 3 – 15 times per section. For drilling a hole with 3 sections, the total time is 36 – 180 hours. With a hourly rate of NOK 200.000, the cost will be NOK 7,2 mill  –  35 mill)​ for the drilling operation.

Solution

For a horizontal well, MudSim makes it possible to drill the well and circulate drilling fluid simultaneously, with acceptable hole cleaning performance. This is achieved by adjusting drilling fluid parameters, especially viscosity and pump flow rate, continuously during drilling.