Production Monitoring of Multilateral Wells by Quantum Marker Systems

Reliable information about the inflow composition and distribution in a multilateral well is of great importance and an existing challenge in the oil and gas industry. In this paper, we present an innovative method for dynamic monitoring of inflow profile based on quantum marker technology in a multi-lateral well located in West Siberia. Marker systems were placed in the well during the well reconstruction by horizontal side tracking with the parent borehole remaining in production. This way of reconstruction allows development of the reservoir drainage area with a lateral hole and bringing the oil reserves from the parent borehole into production, which results in an increased flow rate and improved oil recovery rate. Placement of marker systems into parent borehole and side-track for fluid distribution monitoring allows to evaluate the flow rate from every borehole and estimate the effectiveness of performed well reconstruction. Marker systems are placed into the parent borehole as a downhole sub installed into the well completion string. For the side-track polymer-coated marked proppant was injected during hydraulic fracturing to place markers. The developed method was reliably used for an accurate and fast determination of the inflow distribution in a multi-lateral well which allows more efficient field development and also enabled us to provide effective solutions for following challenges: Providing tools for timely water cut diagnostics in multilateral wells and information for water shut-off method selection; Selecting the optimal well operating mode for effective field development and premature flooding prevention in one or both boreholes; Evaluating whether well construction was performed efficiently, and an increased production rate was achieved; Leading to a considerable economic savings in capital expenditure.

Angular correlations of causally-coherent primordial quantum perturbations

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular scales. It is shown that causal coherence can lead to less cosmic variance in the large-angle power spectrum ${C}_\ell$ of primordial curvature perturbations on spherical horizons than predicted by the standard model of locality in effective field theory, and to new symmetries of the angular correlation function ${C}(\Theta)$. Causal considerations are used to construct an approximate analytic model for ${C}(\Theta)$ on angular scales larger than a few degrees. Allowing for uncertainties from the unmeasured intrinsic dipole and from Galactic foreground subtraction, causally-coherent constraints are shown to be consistent with measured CMB correlations on large angular scales. Reduced cosmic variance will enable powerful tests of the hypothesis with better foreground subtraction and higher fidelity measurements on large angular scales.

Dynamic magnetic birefringence in a viscoelastic ferrocolloid

A model is developed to describe the oscillations of optical anisotropy induced in a viscoelastic ferrocolloid (nanodispersion of magnetic particles) by an AC magnetic field. The viscoelasticity of the matrix (carrier medium) is assumed to obey the Jeffreys rheological scheme, whose advantage is that with the aid of just two viscous parameters and a single one for elasticity it enables one to vary the retarded mechanical response of the carrier from a weakly Maxwellian fluid to a medium with the rheology of a Kelvin gel. As the orientational motion of the particles driven by the AC field is always strongly affected by thermal motion, the occurring process is described with the aid of a kinetic (Fokker–Planck type) equation that combines diffusional and drift terms. On this basis, an exact evolution equation for the macroscopic optical anisotropy of a ferrocolloid is derived that is, however, just one link in an infinite chain of equations for statistical moments. The solution is obtained by applying effective field approximation: reducing the number of moment equations to their minimum and closing the chosen set. This solution is substituted to the scheme of a standard polarimetric set-up, and it is demonstrated how the peculiarities imparted by viscoelasticity should manifest themselves on the intensity of the light transmitted through the set up containing a ferrocolloid sample. This article is part of the theme issue ‘Transport phenomena in complex systems (part 2)’.