Operational Value - Devex Conference

Cross discipline use of the Modular Formation Dynamics Tester (MDT) in the North Sea John Costaschuk, Dann Halverson, Andrew Robertson Res. Eng. Petrophysicist Geologist

Content • Defining the Value of Information and the Functionality of the Modular Formation Dynamics Tester (MDT) • Examples of value creation within BP’s North Sea operations: A. Operational Value

B. Subsurface Value

InSitu Fluid IFA & Asphaltene EoS Analysis Vertical Interference Test (IFA) • Summary and Conclusions

C. Project Value

Acquisition of live microbial samples

Defining the Value of Information • Many E&P decisions are difficult to make, involving significant capital expenditure for uncertain gain. • Value enhancement comes from allowing more robust decisions to be made, as a result of more reliable forecasting of the uncertain parameters and outcomes.

− Operational − Subsurface − Project • Value of Information (VoI) compares the value associated with a decision, informed with and without extra information. • The reliability of the additional data is crucial to understand.

The Functionality of the Modular Formation Dynamics Tester (MDT) Conventional openhole pressure data is difficult to interpret in some areas of the resource: • Depletion signal impacts interpretation • Low matrix perm in parts of the reservoir

High Pressure Pump Focused Sampling Probe

Large Diameter Probe Guard Fluid Analyser for focused sampling

* (IFA) InSitu Fluid Analyser

Reservoir Formation

InSitu Fluid Analyser

Reservoir Formation

Adding IFA* data increases reliability of the fluid interpretation: • Viscosity • Optical Density • Fluid Density • Resistivity

Sample Chambers

Operational Value of MDT

Operational Value of IFA:

A. Operational Value

• • • •

Rapid determination of fluid contacts Allows on the fly programme modification B. Subsurface C.modification Project Value Allows on the flyValue well test design Resultant time cost saving on data acquisition.

Conversely allows you to optimise a programme when you only have a very limited time window. Recent appraisal experience: Insitu Fluid Analysis (IFA)

• IFA The&top ranked objective of a well was to confirm OIP asphaltene EoS Acquisition of live by establishing FWL within the segment microbial samples Test that a reliable •Vertical It wasInterference critical to ensure free water sample was captured before weather terminated the operation.

Operational Value of MDT IFA confirmation that well objective met

• What is the critical time estimate for clean-up, before which quality samples can be taken? Is the rock of adequate mobility? • Should the sample point be re-placed along the open-hole environment and clean-up restarted? • Under poor weather conditions, when have the objectives been met, and thus can the run be terminated?

Operational Value of MDT IFA confirmation that well objective met

Shut-in

Resistivity

Shut-in

Density

Operational Value of MDT IFA confirmation that well objective met Well Objective (#1)

•

Confirm OIP by establishing FWL within segment.

IFA Observation •

FLOWING: Resistivity saturated up to 6900s, but after this resistivity drops in spikes: non-continuous water phase (droplet) becomes more continuous; relatively low viscosity bulk phase

•

SHUT-IN: After the pumps are stopped at 10600s two immiscible fluids appear to segregate in the flowline, and a water density is measured at the AFA sensor at the bottom of the flowline

IFA Interpretation •

Mixed flow of two immiscible fluids when sampling − Free water phase − Oil phase or mud filtrate

Reliable Information

8

Subsurface Value of MDT IFA integration with lab and depletion data Reliable Information

Subsurface Value of IFA and asphaltene EoS: − Alternate matches to the petroleum system model − Connectivity and compartmentalisation

A. Operational Value

Insitu Fluid Analysis (IFA)

B. Subsurface Value

IFA & asphaltene EoS Vertical Interference Test

C. Project Value

Acquisition of live microbial samples IFA Data Pressure Data

Subsurface Value of MDT Vertical Interference Test Data Subsurface Value of Vertical Interference Test data:

− Uncalibrated petrophysical model A. Operational Value

Insitu Fluid Analysis (IFA)

− DST test / no test decision required B. Subsurface Value C. Project Value − Kh and Kv/Kh uncertainty in missing core interval

IFA & asphaltene EoS Vertical Interference Test

Acquisition of live microbial samples

Project Value of MDT Acquisition of live microbial samples Project Value in acquisition of live microbial samples

A. Operational Value

Insitu Fluid Analysis (IFA)

• Reduce uncertainty on reservoir souring mechanism and evaluate injection water design options B. Subsurface Value C. Project Value

Recent appraisal experience: • A specialised bottle preparation and sample handling protocol has been developed between BP, OilPlus and Schlumberger  Pressurised water samples are not required for molecular work IFA asphaltene water EoS samples are required for  &Pressurised Acquisition of live transferring and setting upmicrobial the culture samples Vertical Interference Test • After three months incubation of the pressurised culture no significant hydrogen sulphide generation was observed (multiple bottles for each penetration).

Summary and Conclusions • Operational Value of InSitu Fluid Analyser (IFA): − When and where to sample relative to well objectives • Subsurface Value of IFA & asphaltene Equation of State: − Alternate matches to the petroleum system model − Connectivity and compartmentalisation • Subsurface Value of Vertical Interference Test data: − DST test / no test decision − Kh and Kv/Kh in missing core interval • Project Value of acquisition of live microbial samples

Questions • Thank you for your attention and interest.

Credit: Paul Roylance & Gavin Fleming (Operations Geologists) Ilaria de Santo & Jonathan Haslanger (Schlumberger) Keith Robinson & Richard Jonson (Oil Plus)