Negative Testing Why & how?

Inflow (Negative) Testing

Why & how?

When drilling the well and running tubulars, the drilling fluid will have a higher densitythan the reservoir/formation fluids to prevent any hydrocarbon influx. Prior to running in the production completion, the well is displaced to a lighter density completion fluid to encourage the hydrocarbons to flow into the wellbore and up the production tubing.

If any integrity issues in the connections or the casing/liner overlap are present this could affect the overall efficiency of well production recovery, in addition to posing safety & integrity issues of the well construction. Hydrocarbons could potentially by-pass any safety related equipment in the well completion string. By carrying out an inflow test, the well is allowed to go into an underbalanced state in a controlled manner, to check for any leaks in the liner tubular connections and/or the casing/liner overlap. As the well is not completely displaced to the completion fluid if any leaks were to be found the well can be kept under control at all times. The well can then be displaced back to the initial well fluid in a safe and controlled manner to allow remedial work to be carried out where required.