Drilling Formation Tester (DFT)

The Drilling Formation Tester (DFT) can make multiple reservoir pressure tests to provide information to the reservoir engineer at any time during the drilling of the well. Pressure measurements made in the relatively un-invaded reservoir, reflect conditions prior to damage due to migration of fines and irreparable.

The zones of interest are located using our gamma and/or resistivity sensors. The DFT may be used in the drilling mode or on a wiper trip or hole conditioning run.

System Operation

While drilling, the DFT tool is in “sleep mode”, but capable of transmitting annulus pressure to the surface. At this point the required test points are identified using one or more LWD sensors. The LWD operator will instruct the tool to switch to test mode once in the correct position, thus initiating the automated test sequence.

The flow diverter will open after activating thus re-directing mud flow from the drill bit to above the packer elements. This allows the packers to be inflated in the static mud environment while still maintaining flow over the upper BHA assembly. Once the packers are inflated, the drawdown pump begins to remove trapped fluid. At each stroke, the pump will remove 100cc of fluid, a typical test removing 10-20 liters before formation pressure is allowed to build back to the steady state condition.

Data is transmitted throughout the test to the surface in real-time by using the MWD system and stored in high-density memory for further analysis on return to the surface.

When the test is complete the packers retract, the diverter closes and another test may be performed. The tool can also be put back in “sleep mode” and drilling resumed.

Technical Data Sheets

• Technical Data Sheets (PDF)

Case Histories

• Gulf of Mexico (PDF)
• North Sea (PDF)

Technical Discussions

• Applications for an LWD Formation Tester