Mitigate borehole stability issues while acquiring images of fracture
Mabruk Oil Operations has been developing what is considered to be one
of the most complex offshore fields in Libya due to gas and water breakthrough.
The carbonate field is structurally complicated with complex fracture networks.
Mabruk Oil Operations has developed the field with an innovative perforation
strategy based on image interpretation to reduce gas as well as water
breakthrough coming from faults and open fractures.
In previous operations, wireline-conveyed services were used to acquire
images for designing perforations to avoid fractured intervals with aperture
width smaller than 0.1 in. For the field, this method of conveyance had become
complicated because of severe mud losses and borehole instability on
extended-reach wells. Mabruk Oil Operations and Schlumberger worked together to
test a new LWD technology by running both wireline and LWD for validation of
accuracy and to find a solution to minimize well stability risks in future
Acquire high-resolution images for sedimentological analysis with LWD
In the same 6-in horizontal section of the well, the team acquired both
wireline and LWD images to be used for sedimentological analysis. The LWD
service was MicroScope HD high-resolution image-while-drilling service, which
is capable of 0.4-in vertical-resolution resistivity images in water-base mud
(WBM) environments. The wireline service used to validate the LWD imaging was
logged on the TLC tough logging conditions system to enable measurements in the
lateral drain. MicroScope HD service logged the well on wash-up mode.