Schlumberger

CHDT Cased Hole Dynamics Tester

The CHDT cased hole dynamics tester conducts multiple pressure measurements and collects fluid samples behind the casing, including effectively plugging the hole drilled in the casing to restore pressure integrity. Our reservoir evaluation experts meet with you to design the tester configuration and specify test procedures for determining productivity and permeability along with fluid extraction and sampling. We monitor in situ pressure and fluid measurements in real time to ensure that the job objectives are met. Our multidisciplinary interpretation experts then work with you as needed to leverage this data with advanced workflows and access to proprietary software, including the Techlog wellbore software platform.

Because the CHDT tester efficiently drills through the casing and cement to access the formation and its fluids—unlike traditional cased hole formation testers, which rely on explosive charges to establish communication with the formation—there is no explosive shock compromising the seal between the tester and the casing to prevent obtaining valid pressure measurements, conducting pretests, or sampling fluids. Conventional cased hole pretests are also difficult to analyze because the penetration depth of the explosive charges is uncontrolled.

The InSitu Fluid Analyzer system can be deployed with the CHDT tester to comprehensively measure the sampled fluid at reservoir conditions, spanning direct indicators of fluid sample purity to extensive downhole fluid analysis (DFA).

Interpretation Services for CHDT Cased Hole Dynamics Tester
Wellsite Answers

Formation pressure

Drawdown mobility

Downhole fluid analysis:  fluid color and compositional analysis, asphaltenes content, viscosity, density, florescence, resistivity, and pH

Hydrocarbon composition (C1, C2, C3–C5, and C6+)

Gas/oil ratio (GOR) 

Sample contamination monitoring
Standard Interpretation

Grading of pressure and mobility quality

Pressure gradient analysis

Excess pressure analysis
Advanced Interpretation

Multiwell pressure gradient analysis

Single-well simulation for absolute open flow potential (AOFP)

Determination of vertical permeability and identification of flow barriers

Reservoir connectivity studies using downhole fluid analysis and equation-of-state modeling

Related services and products

 
 

Real-Time Downhole Fluid Analysis

InSitu Density
InSitu Family quantitative fluid properties measurements are made at reservoir conditions: density, composition, gas/oil ratio and condensate/gas ratio, CO2, color, fluorescence, and pH.
Visit InSitu Family page

Limiting Pressure Drawdown Controls Shock Effects

The CHDT station log shows the pressure response (blue) during a low-shock sampling job. The log also details the pumpout volume response (gray).
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