INTRODUCING CORE-SHELL TECHNOLOGY FOR CONFORMANCE CONTROL

Reservoir heterogeneities can severely affect the effectiveness of waterflooding because displacing fluids tend to flow along high-permeability paths and prematurely breakthrough at producing wells. A Proof-of-Concept (PoC) study is presented while discussing the experimental results of a research on "core-shell" technology to improve waterflooding in heterogeneous oil reservoirs. The proposed methodology consists in injecting a water dispersion of nanocapsules after the reservoir has been extensively flushed with water. The nanocapsules are made of a "core" (either polymeric or siliceous materials), protected by a "shell" that can release its content at an appropriate time, which activates through gelation or aggregation thus plugging the high permeability paths. Additional flooding with water provides recovery of bypassed oil. The initial conceptual screening of possible materials was followed by extensive batch and column lab tests. Then, 3D dynamic simulations at reservoir scale were performed to compensate for the temporary lack of pilot tests and/or field applications

Synthesis and comparative characterization of Al, B, Ga, and Fe containing Nu-1-type zeolitic framework

We synthesized four different Nu-1-type zeolites containing, respectively, Al, B, Ga, and Fe as the trivalent element. With the exception of B-Nu-1, the synthesis is difficult because of the competitive formation of other crystalline phases as sodalite, ZSM-39-type, or glassy phases. The trivalent elements isomorphous substitution was demonstrated by X-ray powder diffraction, FTi.r., e.s.r., u.v.-Vis., and 27Al, 11B, and 71Ga-MAS-n.m.r. By the same techniques and t.g.a. measurements, we evaluated the thermal stability of the different Nu-1-type zeolites

Use of X-Ray saturation measurements in flow-through investigations for the characterization of two- and three-phase relative permeability of carbonate rock

We illustrate the results of a suite of laboratory-scale experimental investigations of multi-phase (oil/ water/ gas) relative permeabilities. Two- and three-phase relative permeability data are obtained on a core of Portland limestone by way of a Steady-State (SS) technique. Our laboratory methodology allows improved relative permeability acquisition through a joint use of traditional flow-through investigations and direct X-Ray measurement of the core local saturation distribution. The latter renders detailed distributions of (section-averaged) fluid phases along the core, which can then be employed for the characterization of relative permeabilities. The three-phase Steady-State relative permeability experiments have been conducted by resorting to a dual energy X-Ray methodology. The experimental setup also includes a closed loop burette system to validate and support saturation measurements/estimates. The three-phase experiments are performed by following an IDI (Increasing- Decreasing - Increasing) saturation path. The study demonstrates the capability of the methodology to obtain reliable two- and three-phase data for model calibration and simulation

A simple synthesis of aaptamine, a 1H benzo(de) 1,6 naphthiridine alkaloid

Aaptamine, a 1H-benzo[de][1,6]-naphthyridine alkaloid, is prepared by the triphenylphosphite reduction of a vinylic nitro derivativ

The bis(salicylaldehyde)ethylenediimine cobalt(II)-catalyzed oxidative carbonylation of 1-adamantylamine in alcohol: a study for optimizing carbamate formation

The oxidative carbonylation of 1-adamantylamine with dioxygen and carbon monoxide in methanol and with bis(salicylaldehyde)ethylenediimine cobalt(II) as catalyst to give the corresponding carbamate and urea is sensitive to the reaction temperature, the [substrate]/[catalyst] ratio and the pressure of the reactants. In the same conditions, diphenylmethane and anthracene exhibit only oxidation to benzophenone and anthraquinone respectively, and the antitumoral drug 3,6-diamino-2,7-dimethylacridine (acridine yellow) gives the corresponding monocarbamate

Numerical assessment of water alternating gas practices in the presence of hysteresis effects on relative permeability

Water Alternating Gas (WAG) injection is one of the most successful enhanced oil recovery approaches. Properly accounting for the hysteretic effects of relative permeabilities is a critical issue encountered in numerical simulations of WAG at the mesoscale. Ranaee et al. (2015) proposed a sigmoid-based model for three-phase oil relative permeability, incorporating key physical effects taking place at the pore scale. The model can then be jointly used with the Larsen and Skauge (1998) model, accounting for gas relative permeability hysteresis, to develop a formulation for three-phase relative permeability suitable for reservoir simulation. In this study we illustrate the impact of this joint formulation on a field scale setting through a suite of numerical simulations of WAG injection targeting a reservoir model inspired to real life cases. The analysis is performed by embedding the illustrated relative permeability models in the black oil model implemented in the Matlab Reservoir Simulation Toolbox (Lie et al., 2011). We assume non-hysteretic behavior for water relative permeability under water-wet conditions and characterize it upon relying on corresponding laboratory-scale data. As a baseline, the results are compared against a scenario in the absence of three-phase relative permeability hysteresis. The computational domain is heterogeneous, the spatial distributions of porosity and absolute permeability varying across the ranges of [0.02-0.3] and [0.1-2600 mD], respectively. The model is set at equilibrium conditions, production being driven by three peripheral injectors and five up-dip producers. A given flow rate is assigned to each injector and a target value of liquid production rate is imposed at the producing wells. The numerically evaluated production rates constitute our target state variables. The schedule of the injectors is set to achieve a preliminary waterflooding phase followed by a WAG injection scheme. The latter is implemented by periodically switching the injected phase between water and gas for two injectors, the third injector continuously injecting water. The numerical simulations are performed through a fully implicit discretization of the equations governing the system dynamics. To minimize computational costs, we employ an algebraic multi-grid method and resort to a multi-processor high performance clustered computer system. Our results suggest that hysteretic effects are important across significant portions of the studied reservoir system. Field production responses are associated with a simultaneous increase of ultimate oil recovery and a corresponding decline of the gas-oil ratio when hysteretic effects are included in the simulations

A radiofrequency/microwave heating method for thermal heavy oil recovery based on a novel tight-shell conceptual design

The ongoing depletion of light oil resources and the increasing global energy demand is driving oil&gas companies towards the exploitation of unconventional oil resources. In order to extract crude oil from these resources, a sufficiently low oil viscosity must be achieved, for instance through temperature increase. Electromagnetic irradiation through downhole antennae can be a suitable method for in situ heating of reservoirs. Potential problems for this technique are the extremely high temperatures that can be reached at the well containing the radiating element and the strong dependence of temperature profiles on local variation of reservoir material properties. These problems can be solved to a large extent by inserting around the radiating well a tight shell made of a low loss dielectric material, and by selecting the proper irradiation frequency. The experimental work described in this paper aims to verify the effectiveness of a similar structure during the electromagnetic heating of over 2000 kg of oil sand in a sandbox up to 200 °C, using a dipolar antenna. Oil sand was irradiated at 2.45 GHz frequency with variable power (1–2 kW). The temperature in the oil sand mass and on the boundary were recorded throughout the test in several specific points, in order to estimate temperature profiles along the distance from the antenna. Experimental results confirmed that the presence of the low lossy material shell realized around the antenna is extremely efficient in lowering the temperature in this critical zone and in better distributing the irradiated energy in the oil sand mas