Best Practice Methodology to Enhance Modeling Inflow Control Technologies in Dynamic Reservoir Simulators

The methodology presented here will expand on current modeling of Autonomous Inflow Control Devices (AICD) to generalize for a wider range of fluid flow rates and phases. It will also address the challenges of modeling multiphase behavior of the reservoir fluid flow. This paper presents proposed methods for selected devices, and device models supported by simulations. The proposed methods show the potential for qualified benchmarking of Inflow Control Technology (ICT) completed wells in dynamic reservoir simulations compared to the generic models currently in use. New single-phase models for segregated and sequential flow are presented, and these have a potential for greatly simplifying mass flowrate predictions for multi-phase flow leading to more accurate analysis within dynamic reservoir simulators.

New Metallic Damper with Multiphase Behavior for Seismic Protection of Structures

This paper proposes a new metallic damper based on the plastic deformation of mild steel. It is intended to function as an energy dissipation device in structures subjected to severe or extreme earthquakes. The damper possesses a gap mechanism that prevents high-cycle fatigue damage under wind loads. Furthermore, subjected to large deformations, the damper presents a reserve of strength and energy dissipation capacity that can be mobilized in the event of extreme ground motions. An extensive experimental investigation was conducted, including static cyclic tests of the damper isolated from the structure, and dynamic shake-table tests of the dampers installed in a reinforced concrete structure. Four phases are distinguished in the response. Based on the results of the tests, a hysteretic model for predicting the force-displacement curve of the damper under arbitrary cyclic loadings is presented. The model accurately captures the increment of stiffness and strength under very large deformations. The ultimate energy dissipation capacity of the damper is found to differ depending on the phase in which it fails, and new equations are proposed for its prediction. It is concluded that the damper has a stable hysteretic response, and that the cyclic behavior, the ultimate energy dissipation capacity and failure are highly predictable with a relatively simple numerical model.

An Experimental Study of Multiphase Behavior for n-Butane/Bitumen/Water Mixtures

Summary Steam/solvent coinjection has been studied and pilot tested as a potential method to improve steam-assisted gravity drainage (SAGD) for bitumen recovery. Reliable design of coinjection requires reliable pressure/volume/temperature (PVT) data for bitumen/solvent/water mixtures, which are scarce and fragmentary in the literature. The main objective of this research was to present a new set of PVT and multiphase data for n-butane/Athabasca-bitumen/water mixtures at pressures up to 10 MPa and temperatures up to 160°C. Experiments were conducted with a conventional PVT apparatus. The data presented include multiphase equilibria up to four coexisting phases and liquid densities for 100% bitumen, two mixtures of n-butane/bitumen, and one mixture of n-butane/bitumen/water. Liquid/liquid separation of hydrocarbons was experimentally observed at the n-butane concentration of 97 mol% in the n-butane/bitumen system with/without water, for a wide range of temperatures at operating pressures for expanding-solvent SAGD (ES-SAGD). This may indicate the limited solubility of n-butane in bitumen even when a high level of accumulation of n-butane takes place near a chamber edge in ES-SAGD for Athabasca bitumen. The multiphase transition that involves appearance/disappearance of the vapor phase was observed to occur near the vapor pressure of n-butane or its extension. Such phase transition occurs at a higher pressure in the presence of water, because of its vapor pressure, than in the absence of water at a given temperature. This is the first time four coexisting phases are reported for n-butane/Athabasca-bitumen/water mixtures at temperature/pressure conditions relevant to ES-SAGD.

A New Algorithm for Multiphase-Fluid Characterization for Solvent Injection

Summary Compositional simulation of solvent injection requires reliable characterization of reservoir fluids by use of an equation of state (EOS). Under the uncertainty associated with nonidentifiable components, reservoir fluids are conventionally characterized in the absence of universal methodology. This is true even for relatively simple fluids involving only the gaseous (V) and oleic (L1) phases. No systematic method has been presented for characterization of more-complex fluids, exhibiting three hydrocarbon phases: the V, L1, and solvent-rich-liquid (L2) phases. This paper presents a new algorithm for systematic characterization of multiphase behavior for solvent-injection simulation. The reliability of the method comes mainly from the binary-interaction parameters (BIPs) newly developed for the Peng-Robinson (PR) (Peng and Robinson 1976, 1978) EOS to represent three-phase behavior, including upper critical endpoints, for n-alkane and carbon dioxide (CO2)/n-alkane binaries. The regression part in fluid characterization broadly follows the concept of perturbation from n-alkanes, which was successfully applied for simpler two-phase fluids in our prior research. The algorithm, in its simplest form, uses only the saturation pressure and liquid density at a given composition and reservoir temperature. Case studies are presented to demonstrate the reliability of the algorithm for 90 reservoir fluids and their mixtures with solvents. Predictions are compared with experimental data for up to three phases. Results show that the simple algorithm developed in this research enables the PR-EOS to predict multiphase behavior in spite of the limited data used in the regression. Without the use of the BIPs developed in this research, the PR-EOS may fail to predict three phases, or may provide erroneous three-phase predictions.