Longshen 305-1

Well Number: Longshen 305-1 Drilling Crew: Great Wall 50640 Instrument Style: HT-LWD 350
Description of Well Condition:
Longshen 305-1 is designed as third spud, the second spud borehole size is 215.9mm, the third spud borehole size is 152mm, program depth of the well is 5440m, vertical depth is 4500m, kick off point is 3320m. Longshen is a high inclination and large displacement well. It’s the first large displacement in Natural Gas Dept. of Jinlin Oilfield, with designed displacement for 1553m. This area’s geothermal gradient is as high as 3.7℃/100m, so it is very difficult for construction. The estimated drilled well bottom temperature is 170℃, which brings great challenge for measurement of instrument.
Operating Situation of HT-LWD350:
1. In February 24 2013, the instrument was descended into well. The initial well depth was 3900m, and bottom static temperature was 130℃. Till May 10 2013, the well depth was 4950m, and circulating temperature was 138℃. The instrument operated 1960 hours without any failure.
2. After the down-hole instrument was taken out, disassembled and checked, the pulser and probe’s ground tests showed normal. Spare parts was normal without any erosion. The spare parts were assembled again without exchange, waiting for next descending.
3. The instrument was descended into well, operated smoothly. The well depth was 4950m. The pulse signal was strong, transmission speed was fast and error rate was low.
4. After descending instrument into well, pump pressure was 15-20 MPa. There were 30 trips done when well depth is from 3900m to 4950m. The instruments worked downhole 1690 hours and operated normally with high temperature, high pressure, violent vibration and other complicated circumstance.