Wiper trips are the current field practice to clean the hole for coiled tubing drilling or sand clean out operations. A wiper trip can be defined as the movement of the end of the coiled tubing in and out of the hole, a certain distance. In order to clean the solids out of the wellbore, a proper wiper trip speed should be selected based on the operational conditions. There is no previously published information related to the selection of the wiper trip speed. In this study, numerous laboratory tests were conducted to investigate wiper trip hole cleaning and how the hole cleaning efficiency is influenced by solids transport parameters such as; a) Nozzle Type, b) particle size, c) fluid type, d) deviation angle, e) multi-phase flow effect. The results indicate the following:
Compared with stationary circulation hole cleaning, the use of the wiper trip produces a more efficient clean out.
For a given operational condition, there is an optimum wiper trip speed at which the solids can be completely removed.
Nozzles with a correctly selected jet arrangement yield a higher optimum wiper trip speed and provide a more efficient clean out.
The hole cleaning efficiency is dependent on the deviation angle, fluid type, particle size, and nozzle type.
Correlation's have been developed that predict the optimum wiper trip speed and the quantity of solids removed from and remaining in the wellbore for given operating conditions. The wiper trip provides an advantage for hole cleaning and can be modeled to provide efficient operations.