Support the pipe in place – Further drilling – Production Protect the pipe in place – Corrosive formation fluids Hydraulic isolation – No communication between different formation fluids – No migration of formation fluids to surface – No loss of production to thief zones
Challenges in Cement Evaluation
Cements ranges widely in property – Foam to high density cements – Contaminated cements Cement placement quality depends on – Well construction – Cement design and execution – Formation pressure, fracture gradient & fluid migration behavior Annulus geometry varies – Casing centralization
Cement Evaluation: Reducing uncertainty Resolve ambiguity through multiple measurements
Address the wide range of cements that could be potentially placed Confirm vertical continuity of cement placement to isolate zones
Service built on USI Ultrasonic hardware Combines USI measurement with 2 nd flexural attenuation measurement: – Used with USI cement acoustic impedance to characterize SLG (Solid-Liquid-Gas) model
Improved evaluation of Light Weight and contaminated cements Circumferential imaging, up to formation or second casing
e c n a d e p m I c i t s u o c A
l a r u x e l F
Isolation Scanner - Material identification in annulus
Far Near USI
Tx
Independent measurements to define annulus material in 1 of 3 SLG (Solid-LiquidGas) states, limiting reliance on thresholds SLG = Acoustic Impedance + Flexural Attenuation
Isolation Scanner strengths – Retains USIT answers – Adds flexural attenuation measurement – Improved sensitivity to light and contaminated cements – Extends cement evaluation to pipe thickness up to 0.8”
Benefits – Quantitative & azimuthal cement map (S-L-G) – Annulus velocity, pipe centralization – Identify presence of channels and impact to zonal isolation – Pipe inspection with cement evaluation
Value to operators –
Reduced uncertainty on cement placement and zonal isolation decisions
IPTC 10546
Isolation Scanner - Third Interface Echo (TIE)
1st Echo
Physical measurement of casing standoff in %
Cement sheath pseudo-thickness
3rd Echo
Mud Casing Cement
Transducer
Formation
Estimated wave velocity - confirm the SLG map and better understand cement placement
3D annular geometry imaging - improved zonal isolation determination Support for improved completion, kickoff, CSG retrieval and remedial strategy
Reducing uncertainty in hydraulic isolation – Isolation Scanner Annulus cross-section shows a marginally thinner cement on one side, but still confirms the presence of a solid cement sheath
Requires the ability to – – – –
Confirm vertical continuity of cement for zonal isolation Confirm adequate pipe centralization Confirm azimuthal cement and absence of channels Resolve ambiguity through multiple measurements
