Using Report of HT-MWD650 Instrument for High Density Well
Well Number: Yuanlu 303 Drilling Crew: Shengli 70178
Instrument Style: HT-MWD 650
Description of Well Condition:
Yuanlu 303, construction borehole size is 215.9mm, measured depth is 4757, vertical depth is 4443m, and kick off point is 3770m. The program maximum density is 2.25g/cm3 , which increases difficulty for transmission of pulse signal. The well equipped with turbo-drill in case to improve rate of penetration which provided high pump pressure. The well’s high pressure, high density increase difficulty for construction. Measure while drilling instruments faces great challenges.
Operating Situation of HT-MWD350:
1.On 4:00 November 30 2012, the instrument was descended into well. The initial well depth was 3545m. Mud density was 1.70g/cm3 .Till 12:30 January 27 2013, when the instrument was taken out, the well depth was 4228m. The maximum density was 2.25g/cm3 .The instrument operated 1133.5 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.
3. The instrument was descended into well, operated smoothly. The mud density reached 2.25g/cm3 depth, while the instrument still operated smoothly. Transmission speed was fast and error rate was low. The dynamic deviation and azimuth precision meet the construction requirements.
4. After descending instrument into well, there were 10 trips done when well depth is from 3545m to 4228m. The instruments worked downhole 1133.5 hours without any failure. The reliability of instrument ensured the successful construction.
5. Every HT-MWD indicator showed better condition than other MWD system. HT-MWD gained praise of construction party and significantly saved drilling period of this well.