Wireline Formation Testers

By

Dr. Jorge Salgado Gomes

Lecture Outcome

• Purpose of wireline formation testers

• History of formation testers

• Multiple configurations

• Pressure evaluation

• Evaluation of permeability

• Determination of fluids and fluid contacts

• Assess reservoir continuity

FTFormation

Tester

RFTRepeat

Formation Tester

MDT ModularFormation Dynamics

Tester

1955 - 1975 1991 - PresentNew Generation

1975 - Present

DualPacker

Electrical Power

Hydraulic Power

Probe

Pumpout

Dual-probe

Flow control

Optical Fluid Analyzer

Multisample

Sample

Sample

History of

Formation Testers

Single Probe Multi-Probe Dual Packer

MDT COMMUNICATION WITH THE RESERVOIR

Probe Configuration

Different Configurations

Single Probe Tool

Dual Probe MDT Photo of dual probe

MDT

“Probes”

“Probe”

KV

KH

Formation fluids enter the tool

Observation Probe. Measures Vertical permeability

Observation probe. Measures the horizontal permeability.

Schematic Diagram

MDT in the wellbore

Borehole

wall

Hydraulic pistons to

push the tool

against the formation

“wireline”

3/4/2013 Chap -1 7

Applications: Permeability

KV

KH Flow Pulse

Sink Probe (No CQG gauge)

Vertical Observation Probe

Horizontal Observation Probe

Applications - Permeability determination -Guard probe sampling

-Bulk Compressibility (being developed)

Details of the Tool

MRPA Dual Packer Module

MR PS-BC & CA

MRPA-CA & DA

MRMU-BA

MRML-BA

MRSE-CA & DA

0, Interval Int akeand Tool Zero

+22" to 32" (Varieswi th Ho le Diameter)

+41" to 46" (Varieswith Ho le D iameter)

+78 5/8"

-13" to -18" (Var ieswith Ho le D iameter)

-26" to -3 6" (Var ieswi th Ho le Diameter)

-74 1/4", StrainGauge Measure Point

-87 5/ 8", CQG Measure Point

+61 7/8", Top ofPacker Module

-138 5/8", Bottom of Packer Modu le MRPA Packer Element Selection/Usage Guide

http://ww.sugar-land.spc.slb.com/spc_open/spc_products/rsp/mdt/docu/index.html

Layer

1

Layer

2

L

aye

r 3

A C D E B

Different Combinations

Pressure Recording

on RFT

RFT Sampling Principles

• Sample every porous and permeable

interval

• At least two tests per zone (layer)

• Test every layered zone

• Check hydrostatic (mud) pressure every

test

2250

2300

2350

2400

2450

2500

2550

3400 3450 3500 3550 3600 3650 3700

Dep

th i

n m

ete

rs

Pressure in (psi)

GOC

FWL

0.09 psi/ft

0.35 psi/ft

0.45 psi/ft

Graphical representation

of fluids in the reservoir

from OH log interpretation

MDT pressures versus Depth

Zone with gas

Zone with oil

Zone with water

Pressure gradients are in psi/ft

FWL – “Free Water Level”, determined from MDT

GOC – “Gas Oil Contact”, determined from OH logs and MDT

OWC – “Oil Water Contact”, determined from OH logs

Swi – “Irreducible Water Saturation”>

FWL; difficult

to establish with

OH logs. MDT is

required.

Exact depth of GOC

difficult to establish with

OH logs.

OWC ?

Transition zone:

Water saturation

Increases with depth

Cap

illa

ry P

res

su

re (

Pc

) in

psi

Water Saturation

Separation OWC-FWL

Due to “treshold

pressure”

Graphical representation of

capillary pressure (Pc) versus

depth

Swi

gas

oil

water

gas

oil

water

Reservoir Continuity

Pressure vs Depth to establish

Reservoir Continuity

Pressure vs Depth in-fill Well

Effect of Depletion on

Pressure Profile

Courtesy of Schlumberger

RFT Gauges

Accuracy & Resolution

• ACCURACY

– Strain Gauge 0.41% FS

– (TCO 0.13% = 13 psi)

– HP gauge 0.5 psi (?)

– CQG (MDT) 2 psi + 0.01% reading

• RESOLUTION

– Strain Gauge 1 psi

– Quartz Gauge 0.01 psi

• REPEATABILITY

– Strain Gauge 0.06% FS

– Quartz Gauge 0.1 psi

MDT (Pressures & Sampling)

Formation Pressures

CQG (Quartz) Gauge w/ Dynamic

Compensation

1 psi accuracy (15 Kpsi range)

.003 psi resolution

Controllable Pre-Test

Dual Packer

Multi-Probe Multi-Module

Capability

Vertical Interference testing

Vertical permeability

determination

Mini DST

MiniFrac

Sampling

Numerous Samples (over 30

possible!!)

Pump-out Capability

“Cleanup” prior to sampling

Flowline Resistivity

Optical Fluid Analysis

Real-time downhole fluid

differentiation

Transportable Sample Bottles

Flow Control capability

Dual Packer

“Low Shock” sampling

Single Phase sampling

Nitrogen gas charge to

maintain sample at downhole

pressure