Depleted, Fractured Limestone, Libya
Overview
Geology: Mature Formations, Low Pressure
Pressure Gradient: equivalent 4.5 5.0 ppg @ 5,500 feet.
Previous Wells drilled with low density fluids, underbalanced drilling (UBD
Problems Experienced
Lost circulation
Lost circulation during cementing
Difficulty with logging and using measurement while drilling (MWD)
High Risk of H2S
Solution
AphronICS
Results
AphronICS Successfully drilled to total depth (TD) without lost circulation and eliminated the risk of H2S by maintaining overbalance successful electric logs and exceptional cementing with full returns.
At least 60% of the overall drilling cost was saved, in comparison with planned cost and previous wells cost. Enabled operator to safely further plan the field and served as an effective alternative to UBD.
On the third well the operator changed the well design eliminating the intermediate casing.