Typical Application 1

The EM-MWD System was applied in well JPH393, with drilling sections including pilot hole 0 ~ 3397m and main borehole 2710 ~ 3460m. A total of 11 drilling trips were carried out in the well, and the accumulated working time of the instrument in the well reached 1754.5h (including 769.5h for the repeater), and the longest continuous working time of the downhole instrument reached 220h. During the construction process, the signal of the instrument was stable, and no tripping out caused by tool failure.

Typical Application 2

The EM-MWD System was used in AJ214 well in AGHA JARI block of Ahvaz, southwest of Iran, which was designed depth of 2,855m, sidetrack drilling point of 1,999m, maximum inclination of 63°, and closed azimuth of 64.5°. As the first directional well of NIDC (National Iranian Drilling Company) to explore the underbalanced technology, the well was drilled with fuel oil injected nitrogen drilling fluid (20~25% nitrogen content) with density of 0.77~0.80g/cm³, which made the traditional MWD malfunction. In order to meet the high resistance of gypsolyte formation, the EM-MWD system selected low carrier frequency of 2Hz to ensure stable signal transmission to the surface. Total of 4 drilling trips were carried out in the whole well, the transmitter entered the well for 406h and the repeater worked for 228.5h.