The BU-W01 development well was drilled from the BU-WP1 platform by the Ensco 104 jackup rig. BU-WP1 is located in the eastern half of the Bayu-Undan gas condensate field which is in the Production Sharing Contract (PSC) areas of ZOCA 91-12 and ZOCA 91-13, North Bonaparte Basin, Timor Sea, offshore Northwest Australia. The location of WP1 is approximately 25km south of the production facilities of Elang oil field and 480km northwest of Darwin. ConocoPhillips (91-12) Pty Ltd is the operator.
The Ensco 104 jack-up drilling rig (previously the Chiles Discovery) was on WP1 location on 15th May 2002 in 77.6 meters (LAT) of water depth and a rotary table elevation of 45.4 meters above sea level. All depths are referenced to the Ensco 104 Rotary Table unless otherwise indicated. BU-W01 was spudded in on 22nd May 2002, as part of batch drilling sequence that includes 5 other wells. The well was drilled to the south-east and reached a total depth of 3924 mRT in 8½" hole size on 29th September 2002. BU-W01 was cased and completed with approximately 134 m of net sands to be perforated as a condensate and gas producer. The Ensco 104, once released from BU-WP1 will move to BU-DPP platform. The total number of days at the BUW01 location, prior to perforation and clean up was 62 days.
SAMPLES, SIDEWALL CORES CONVENTIONAL CORES
Drill Cuttings
Ditch cuttings spot samples were collected at 5 or 10 m intervals in the 17 ½" hole section between 808.0 and 2213.0 mMDRT. Composite washed and unwashed ditch cuttings samples were collected for storage at 5, 10 or 20 m intervals in the 12 ¼" and 8 ½" hole sections, between 2213.0 and 3924.0 mMDRT.
BU-W01 Ditch Cuttings Sampling Type and Frequency
Interval mMDRT | Sample Frequency |
| Distribution |
123.7 to 808.0 808.0 to 2213.0 2213.0 to 2220.0 2220.0 to 3450.0 3450.0 to 3500.0 3500.0 to 3540.0 3540.0 to 3570.0 3570.0 to 3660.0 3660.0 to 3920.0 3920.0 to 3924.0 | None None | No returns Spot Samples Washed & Unwashed Washed & Unwashed Washed & Unwashed Washed & Unwashed Washed & Unwashed Washed & Unwashed Washed & Unwashed Washed & Unwashed | N/A N/A Unwashed: ConocoPhillips 1 set East Timor Gov’t 1 set Washed: ConocoPhillips 1 set East Timor Gov’t 1 set Geoscience Aust. 1 set |
Cores:
No conventional cores were cut.
Sidewall Cores:
No sidewall cores were acquired.
LOGGING AND SURVEYS :
Mud logging :
Sperry-sun Drilling Services provided the mud logging services with full surface data monitoring commencing from the 36” hole section and formation evaluation and pressure monitoring services from the 17½” hole to total depth.
LWD Logging
BU-W01 Open Hole FEWD Logging Suites and Intervals
|
Size | Tool
String |
(mMDRT) | Comments |
| 17½” | DDS-BAT-GRPWD-ACAL |
| Pulser / telemetry module failure. |
| 17½” | DDS-BAT-GRPWD-ACAL |
| Sonic tool failure at 1809m. Acoustic Caliper (ACAL) unable to give accurate readings in this hole size. |
| 17½” | DDS-BATPWD-GR-ACAL |
| Pulser failed |
| 12¼” | GR-PWD-DDSBAT-SLD |
|  |
| 12¼” | GR-PWD-DDSBAT-SLD | 3318-3495 | |
| 12¼” | GR-PWD-DDSBAT-SLD | 3495-3675 | |
| 8½” | GR-SLD-EWRP4-CNP-BATPWD-ACALDDS | 3675-3751 | |
| 8½” | GR-SLD-EWRP4-CNP-BATPWD-ACALDDS | 3751-3258 | |
All logging was acquired in cased hole. CGG were used to acquire velocity VSP/Checkshot data in BU-W01 in cased hole on a Halliburton Logging Services (HLS) wireline cable. Halliburton Logging Services (HLS) acquired cased-hole cement bond wireline logs.
Cased Hole Wireline Logging Suites and Interval
| Suite | Run | Tool
String |
(mRT) | BHT/Hours
|
|
1 | 1 | CGG Vertical Incidence Checkshot |
| N/A | Dual BSR-4 geophones run at 30m interval – Rig source only. Tool hung up at 1442m. |
2 | 1 | CGG Vertical Incidence Checkshot |
| N/A | Dual BSR-4 geophones run at 30m interval – Rig and boat source. |
3 | 1 | CAST-FWATGR- CCL |
| N/A | 5 passes were acquired. Tool hung up at 3853.5m. |
3 | 2 | CGG Vertical Incidence Checkshot |
| N/A | Dual BSR-4 geophones run at 30m interval – Rig and boat source. |
Lithological Logging
Deviation Surveys
Directional monitoring for BU-W01 was provided by gyro surveys and Measurement While Drilling (MWD). The maximum hole angle recorded was 46.01° at an azimuth of 135.51°.
Temperature Data
Velocity Survey
FORMATION TESTING AND FLUID SAMPLING
Production Testing
Halliburton will carry out production logging of BU-W01 after completion of all the BU-WP1wells.