Proxy Modeling of the Production Profiles of SAGD Reservoirs Based on System Identification

Large scale physics-based reservoir models are employed routinely in the prediction of the behavior of steam assisted gravity drainage (SAGD) processes under different operational situations. However, parametric uncertainty persists in these models even after history matching with production data. This uncertainty, and the computational cost associated with the full-scale reservoir simulations, makes it challenging to use reservoir simulators in closed-loop control of reservoirs. As an alternative strategy, we present in this work a dynamic proxy model for the reservoirs based on system identification and the prediction error method using only injection and production data. These proxy models are validated against field data from a SAGD reservoir and simulated synthetic reservoir data and shown to be appropriate for use in model predictive control. We also provide evidence that the predictive power of these models can be improved by the appropriate design of input signals (injection rates and pressures)

Typical experimental strain waves of SHTB testing at strain rate of 800 s^-1.

<p>Typical experimental strain waves of SHTB testing at strain rate of 800 s^-1.</p

(a) Stress triaxialities and (b) equivalent plastic strain profiles of smooth and notched specimens at the minimum cross section at the time of fracture.

<p>(a) Stress triaxialities and (b) equivalent plastic strain profiles of smooth and notched specimens at the minimum cross section at the time of fracture.</p

Test photo of MTS electronic universal testing machine.

<p>Test photo of MTS electronic universal testing machine.</p

Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities - Fig 3

<p>(a) Split Hopkinson pressure bar (SHTB) testing apparatus; (b) The geometry of the SHTB-specimen; (c) A notched specimen sandwiched between the incident bar and the transmission bar.</p

The simulated fracture process of a smooth specimen.

<p>The simulated fracture process of a smooth specimen.</p

The chemical compositions of aluminum alloy 6082-T6.

<p>The chemical compositions of aluminum alloy 6082-T6.</p

Flat specimens (a) geometry (b) specimens (unit: mm).

<p>Flat specimens (a) geometry (b) specimens (unit: mm).</p

Engineering stress-strain curves from experiments and ABAQUS/Explicit numerical simulations for (a) smooth specimen, (b) 90 mm, (c) 40 mm and (d) 10 mm notch radius specimens.

<p>Engineering stress-strain curves from experiments and ABAQUS/Explicit numerical simulations for (a) smooth specimen, (b) 90 mm, (c) 40 mm and (d) 10 mm notch radius specimens.</p

True stress-strain curves at strain rate (a) 0.001 s^-1 (b) 0.01 s^-1 (c) 0.1 s^-1 and (d) 1 s^-1.

<p>True stress-strain curves at strain rate (a) 0.001 s^-1 (b) 0.01 s^-1 (c) 0.1 s^-1 and (d) 1 s^-1.</p