The cost savings that are possible by sidetracking existing wellbores make the drilling and completion of ultra slim lateral wells very desirable. Obtaining image logs from horizontal wells, less than 6" diameter, has always been a challenge, because the size of conventional borehole imaging tools that currently exist on the market are simply too large. In addition, conventional deployment methods limit efficient rig time utilization and ultimately lead to higher cost. New conveyance and logging technology from Welltec® (the Well Tractor®) and Weatherford (The Compact Micro Imager - CMI) allows operators to obtain excellent image logs in slim wells as small as 3" in diameter. Image logs are required to properly understand fracture details and to help in future drilling and completion decisions.
This paper describes the logging operational experience of the CMI and the world's first slim hole imaging logs in Saudi Arabia deployed by the wireline tractor 218XR (XR: Extended Reach) in an open hole horizontal section.
Workover operations are a major part of any oil field operator. Well maintenance and repair is performed during workover operations. Repairs include replacement of completion string, casing patch, perforation shut-off, etc. In addition, re-entry and horizontal drilling and open hole completion technology has enabled the operators to increase production and recovery rates from declining fields and short interval pay zones.
Initially the field was developed by drilling vertical producers. The remaining oil column is short and can go as low as 3 to 4 ft in some areas. With field in production, water cut has increased with time. One strategy to save cost of drilling new wells is to re-visit old vertical wells and complete them as horizontal producers.
The re-entry horizontal drilling methodology for Abqaiq field has evolved over time. Due to the original 7" cased hole production completion, a 6??? window is cut for sidetrack in the 7" casing and curve section is drilled to above target formation and a 4½" or 5" liner is run to isolate the high-pressure water formation just above pay formation.
After casing off the curve section, drilling proceeds with 3??? or 4??? horizontal hole in the target formation until reaching total depth (TD).