Warning Signs When Circulating

1
Warning Signs When Circulating
Circulating
Increased drag and resistance
Is increase smooth or erratic?
Smooth
Erratic
Is circulation restricted?
Is circulation restricted?
Y N
Y N
Mobile formations
Do drags increase when not pumping?
Unconsolidated formations Fractured/faulted
formations
Cement blocks Junk
Y N
Mobile formations Reactive formations Geo-pressure
d formations
Inadequate hole cleaning
2
Warning Signs When Tripping In
Tripping In
Increase in downward resistance
Is increase smooth or erratic?
Smooth
Erratic
Is there excessive upward drag?
Is there excessive upward drag?
Hole bridged Can this be related to problem
formations?
N Y
N Y
Inadequate hole cleaning (Cuttings beds)
Was previous bit undergauge?
Is circulation restricted?
N Y
Y N
N Y
Is drag reduced when pumping?
Reactive formations Mobile formations Fractured/fa
ulted formations Unconsolidated formations
Undergauge hole
Formation ledges Wellbore geometry Cement
blocks Junk
Was previous bit undergauge?
Are dog-legs excessive?
N Y
N Y
N Y
Reactive formation Mobile formation
Undergauge hole
Wellbore geometry Formation ledges
Inadequate hole cleaning
Has there been a BHA change on this trip?
Can resistance and drag be related to formations?
N Y
Formation Ledges
Wellbore Geometry
N Y
Cement blocks Junk string Component failure
Fractured/faulted formations
3
Warning Signs When Tripping Out
Tripping out
Increased drag or overpull
Is overpull smooth or erratic?
Smooth
Erratic
Is overpull in new hole section?
Is overpull in new hole section?
Are known problem formations exposed in hole
section drilled by previous bits?
Are known problem formations exposed in hole
section drilled by previous bits?
Are known problem formations exposed in new hole
section?
Are known problem formations exposed in new hole
section?
N Y
Y N
Y N
Y N
N Y
Y N
Unconsolidated- or Fractured/ Faulted formations
Unconsolidated formation Fractured/faulted
and Geopressured formation
Is downward motion possible?
Is downward motion possible?
Is circulation restricted?
Is circulation restricted?
Is circulation restricted?
Is circulation restricted?
N Y
Y N
Y N
Y N
Y N
N Y
Is circulation restricted?
N Y
Can BHA be rotated free?
Cement blocks Junk
Wellbore geometry Formation ledges
Can BHA be rotated free?
Wellbore geometry Formation ledges
Inadequate hole cleaning
Reactive formations (Bit/stabiliser
balling) Mobile formations Unconsolidated
formations
Fractured/faulted formations
Cement blocks Junk
Inadequate hole cleaning
Reactive formations (Bit/stabiliser
balling) Mobile formations Unconsolidated
formations
N Y
N Y
Wellbore geometry Fractured/faulted formation
Key seating
Formation ledges Wellbore geometry
Key seating
Formation ledges Wellbore geometry
4
Warning Signs When Running Casing
Running Casing
Increase in downwards resistance while
running casing or after connection
Can pipe be worked upwards?
N Y
Is circulation restricted?
Is circulation restricted?
Hole packing off Reactive formations Mobile
formations Unconsolidated formations Inadequate
hole cleaning
Hole packing off Reactive formation Unconsolidated
formation
Y N
N Y
Are permeable formations exposed?
Are dog-legs excessive?
N Y
Wellbore geometry
Surface load limitation with respect to larger
drag (especially directional well) Inadequate
hole cleaning (Cuttings beds) Centralisers
broken/bunching
N Y
Differential sticking
Formation ledges Fractured/faulted
formation Inadequate hole cleaning Centralisers
broken/bunching Casing too light (Has not been
filled) Junk in hole
5
Warning Signs When Making Connections
Moving pipe from static after making/breaking
connections during drilling, tripping and reaming
or after surveys
Drag trend increasing when moving string from
static
Is circulation restricted?
Y N
Are known problem formation exposed?
Are permeable formations exposed?
Y N
Y N
Reactive formations Fractured/faulted
formations Mobile formations Unconsolidated
formations Geopressured formations
Junk Cement blocks String component
failure Stabilisers hanging up on ledges
Is drag reduced when pumping?
Can drill string be moved?
Y N
Y N
Reactive formations Fractured/faulted
formations Mobile formations Unconsolidated
formations Geopressured formations
Junk Cement blocks Stabilisers hanging up on
ledges
Inadequate hole cleaning
Differential sticking
6
Warning Signs When Reaming In
Reaming in
Increased torque Increased reaming weight required
Is increase smooth or erratic?
Smooth
Erratic
Is circulation restricted?
Is circulation restricted?
Y N
Y N
Are up drags excessive?
Was previous bit undergauge?
Are hole drags excessive?
Was previous bit undergauge?
Y N
Y N
Y N
Inadequate hole cleaning (Cutting beds)
Y N
Inadequate hole cleaning
Wellbore geometry Formation ledges Junk Cement
blocks Bit failure
Do drags increase when not pumping?
Wellbore geometry (Side-tracking hole?)
Undergauge hole
Undergauge hole
Are drags increased when not pumping?
Mobile formations Reactive formations Unconsolidat
ed formations
Y N
Inadequate hole cleaning
Y N
Unconsolidated formations Fractured/faulted
formations
Inadequate hole cleaning
7
Warning Signs When Running Casing
Running Casing
Increase in downwards resistance while
running casing or after connection
Can pipe be worked upwards?
N Y
Is circulation restricted?
Is circulation restricted?
Hole packing off Reactive formations Mobile
formations Unconsolidated formations Inadequate
hole cleaning
Hole packing off Reactive formation Unconsolidated
formation
Y N
N Y
Are permeable formations exposed?
Are dog-legs excessive?
N Y
Wellbore geometry
Surface load limitation with respect to larger
drag (especially directional well) Inadequate
hole cleaning (Cuttings beds) Centralisers
broken/bunching
N Y
Differential sticking
Formation ledges Fractured/faulted
formation Inadequate hole cleaning Centralisers
broken/bunching Casing too light (Has not been
filled) Junk in hole