SPE 150370Getting the Most out of Networked

DrillstringPetersen, Sui, Frøyen, Nybø

Center for Integrated Operations in the Petroleum Industry & SINTEF

Jackson, Veeningen,

NOV IntelliServ

Agenda

• Downhole data through Networked Drillstrings• Opportunity for modeling• A proof of concept• Conclusions and recommendations

Networked Drillstring

LWD/MWD/RSS Tools

Data measured at surface and in the BHA (MWD)

Conditions along-string inferred or modeled BHA data limited by mud-pulse telemetry rates Almost impossible to accurately monitor entire

wellbore in real-time

Today’s Wellbore Data

Networked Drillstring

LWD/MWD/RSS Tools

Interface SubNetworked Drillstring

Distributed Sensors

Increased bandwidth – via Networked tubulars (wired drill pipe) - bidirectional 56,000 bps

Along string measurements technology Enhanced BHA measurements (density and

quality Accurate & effective real-time decision making

Along-String Distributed Measurements

Using distributed sensor data

• Need a model to interpret the data and to see the implications

• Expect distributed sensor data to: – Provide redundancy– Improve accuracy – Reveal new phenomena

• Most models are designed around measurements at the top and bottom only

Networked Drillstring + Advanced Dynamic Drilling Simulator

• Drilling simulator:– High resolution parameters (fine spatial grid)– Small timesteps– Dynamic 2-D temperature model

• Measurements– Direct: Pressure and Temperature– By combining model and measurements:

• Mud densities, cuttings density, cuttings loading, reservoir fluid type and densities, slip relation, fluid viscosities, wall roughness, heat capacity and conduction, background temperatures, etc.

Divide and Conquer? "Nearly independent" parameters

No Flow•P(h) = g h cos + Ptop

–Integrated density – between measurements• Densities (P,T) information obtained at previous measurements

–Local temperature measurements• Other temperature information given at previous measurements

–From temperature curves – Temperature vs. time• Obtain detailed formation background temperature

Divide and Conquer? "Nearly independent" parameters

Flow•P(h) = g h cos + Pfric + Ptop

–Integrated density – fairly well known from previous measurements–Flow velocity fairly well known from diameters and pump rate–Viscosity and wall roughness can be obtained from Pfric

High rate data acquisition – Model matching: Reliable parameter spaceDeviations

Model data & Measurements mismatch

CausesCuttings loading Open hole washout Kick

Wellbore breathing/Loss of circulation Measurement error Etc.

Each deviation has a separate "fingerprint" and can be discerned using appropriate software.

Experiment

• A real-time drilling simulator has been developed by SINTEF

• The simulator was altered to output data as it would appear from a fictional drilling operation rich in distributed sensors

• The "simulated sensor readings" were input to a simplified wellbore model predicting BHP.

• The simple model was altered to make use of distributed data

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t at bottom

t at 90m above

t at 180m above

t at 270m above

t at 360m above

t at top

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pressure at 90m abovepressure at 180m abovepressure at 270m abovepressure at 360m aboveBHP by flowmodelSPP

Simulated operation:•Pumping 200 l/min for 5 minutes, then stop.•Lowering the bit and tag bottom•Start drilling, pumping 1000 l/min for 60 minutes, drilling at 20 m/hr.•Circulate clean for 60 minutes

Model strategy

Measurement Model estimate

OK? OK?

New model parameter calibrated!

More accurate and reliable BHP prediction

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BH

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BHP by EnKF

BHP by flowmodel

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BHP by proposed method

BHP by flowmodel

Conclusions• By combining redundant measurements in space and

time, we can calibrate the model and get: – A detailed view of the situation along the whole well– Predictive power for the whole well– Safety by redundancy

• The flow around the BHA is a complicating factor– Difficult to calculate BHP from pressure above BHA and

vice versa– Parameters remain uncertain to some degree, since the

sensors don't slide past the BHA components.

Recommendations• Design simulators and that make use of parallel

processing (model tuning & high bandwidth)• Simulate sensor configurations w.r.t: redundancy,

accuracy and ability to detect drilling problems • Consider multiple sensors along the BHA

– More robust and accurate BHP-measurements– Hole-cleaning problems visible in high resolution– Especially relevant for MPD and long open-hole sections

Slide 19 of 5

Thank you