2- filtrate invasion
DESCRIPTION
Filtrate InvasionTRANSCRIPT
2.1- Filtrate Invasion Page-1
2.1- Filtrate Invasion
Depth
Time
Surface Casing, Cementing, Circulation
Surface hole
Intermediate Casing, Cementing, Circulation
Intermediate hole
Production Casing, Cementing, Circulation, Completion, perforations
Production hole
The Drilling ProcessDepth-Time Line
The Drilling ProcessDepth-Time Line
2.1- Filtrate Invasion Page-2
2.1- Filtrate Invasion
OverviewThe hole is drilled in stages and at the end of every stage, casing is put into the hole and cemented into place. After the well has been drilled to final depth and all of the casing has been cemented into place, the well is completed.
2.1- Filtrate Invasion Page-3
2.1- Filtrate Invasion Typical Formation Pressures and the minimum mud density needed to balance this pressure (P = h ρ g)
P= 2000 psi, mud-density= 1.2 gm/cc
P= 3000 psi, mud-density= 1.6 gm/cc
P= 2900 psi, mud-density= 1.4 gm/cc
P= 3500 psi, mud-density= 1.4 gm/cc
P= 4500 psi, mud-density= 1.8 gm/cc
2.1- Filtrate Invasion Page-4
2.1- Filtrate Invasion
Blow Out
Blow Out
Blow Out
Blow Out
What happens if we drill one hole size From Surface to TD and use one mud type:
P= 2000 psi, mud-density= 1.2 gm/cc
P= 3000 psi, mud-density= 1.6 gm/cc
P= 2900 psi, mud-density= 1.4 gm/cc
Mud Density: 1.2 gm/cc
P= 3500 psi, mud-density= 1.4 gm/cc
P= 4500 psi, mud-density= 1.8 gm/cc
2.1- Filtrate Invasion Page-5
2.1- Filtrate Invasion
FractureLost Circulation
FractureLost Circulation
What happens if we drill one hole size From Surface to TD and use one mud type:
P= 2000 psi, mud-density= 1.2 gm/cc
P= 3000 psi, mud-density= 1.6 gm/cc
P= 2900 psi, mud-density= 1.4 gm/cc
Mud Density: 1.8 gm/cc
P= 4000 psi, mud-density= 1.7 gm/cc
P= 4500 psi, mud-density= 1.8 gm/cc
2.1- Filtrate Invasion Page-6
2.1- Filtrate Invasion
BOREHOLE FormationBorehole mud M
ud c
ake
Invaded ZoneFiltrate filled
Virg
in Z
one
Tran
sitio
n Zo
ne
Rt
Rxo
Res
istiv
ityMud
Formation Water
2.1- Filtrate Invasion Page-7
2.1- Filtrate Invasion
Invasion Process1. Mud in the borehole will slowly invade the Virgin Zone2. The solids in the mud will accumulate at the borehole wall (too large
to enter the pores). Some small particles may enter.3. The mud liquid (filtrate) will enter the pores, expels the formation
water and some of the HC4. Progressively, more filtrate will invade the pores5. This invasion process will stop when enough solids accumulate at
the borehole walls create an impervious barrier. 6. We will then have
MudMud cakeInvaded ZoneTransition ZoneOriginal Virgin Zone
2.1- Filtrate Invasion Page-8
2.1- Filtrate Invasion