The Effects of Fluid Viscosity and Density on Proppant Transport in Complex Slot Systems

Summary In this paper, we discuss proppant transport behavior in a complex slot system. Specifically for this study, focus is placed on two different fluid systems, a water/glycerin solution and a water/sodium chloride solution, which represent varying fluid densities and viscosities. The effects of changing fluid viscosities, fluid densities, proppant densities, proppant sizes, proppant concentrations, and slurry injection rates on proppant transport were then experimentally investigated. The slot system consists of a 4-ft long, 0.2-in. primary slot with three secondary slots and two tertiary slots, all at 90° angles to each other. The fluid systems represented brine fluids up to 9.24 ppg and viscous fluids up to 4.3 cp. Although glycerin was used for viscosification, the results can be compared to fluid systems with similar viscosities that are created using other additives such as friction reducers. The proppants used in the study consisted of two sands of 100 and 40/70 mesh (specific gravity of 2.65) and two 40/70 ceramic proppants with specific gravities of 2.08 and 2.71. The study results show that a water/glycerin solution, with a viscosity of 4.3 cp, has significant proppant-carrying capacity with proppants delivered uniformly to greater distances. In addition, sieve analysis conducted on each of the various slots indicated that for all tested proppants that the water/glycerin systems were more capable of carrying larger particles to farther distances. Conversely, the results show that a water/sodium chloride solution of 9.24 ppg density has less capability to carry the proppant farther into the slots. From a comparison standpoint, in all tested cases, viscosity increases had a greater impact on the overall proppant transport than fluid density. In addition, results of the study showed that both increasing proppant concentrations and injection rates have a positive impact on proppant transport, with more proppant being transported farther into the slot system in both cases. The higher the proppant concentration, the sooner the equilibrium dune height (EDH; height when transport starts to occur after dune building) was achieved, the more efficient transport became. Increasing the injection rate led to improving proppant transport by increasing the drag and lift forces on the proppant, which lead to decreased proppant settling velocities and transport farther into the slots.

The Effects of Fluid Viscosity and Density on Proppant Transport in Complex Slot Systems

The main functions of hydraulic fracturing fluids are to create a fracture network and to carry and place the proppant into the created fractures networks, thus, adding to fracture conductivity. Significant research has been performed to develop ideal fracturing fluid systems. The development focus has mainly been on optimization of a fluid rheology that can transport and place the proppant into the primary and any subsidiary fractures with less damage to the formation and at a lower cost. The main goal of this work is to add to the understanding and optimization of proppant transport in complex hydraulic fracture networks. Specifically for this study, focus is placed on two different fluids, water-glycerin solution and water-sodium chloride solution, representing varying fluid densities and viscosities. The effects of changing fluid viscosities, densities, proppant densities, proppant sizes, proppant concentrations, and slurry injection rates on proppant transport were then experimentally investigated. This experimental work shows that viscosity has a greater impact on the proppant transport than fluid density does, thus implying a larger impact on the resulting fracture conductivity. The results of this work show that a water-glycerin solution, with a viscosity of 4.3 cp, has significant proppant carrying capacity with proppants delivered uniformly to greater distances. On the other hand, the results show that a water-sodium chloride solution of 9.24 ppg density has less capability to carry the proppant deep into the fractures indicating that viscosity has a greater impact on the proppant transport than fluid density does. The lab results also showed that increasing proppant concentrations and injection rates has a positive impact on proppant transport.

A Refractive Index Sensitive Liquid Level Monitoring Sensor Based on Multimode Interference

According to the beam propagation method, a fiber refractive index-sensitive multimode interference (MMI) structure fabricated by splicing a self-made silica glass rod between two single mode fibers (SMF–NCF (no core fiber)–SMF structure) is proposed for liquid level monitoring. Theoretical and experimental investigation was carried out meticulously using a 4.5 cm and a 9.5 cm long silica glass rod. It is proved that the simple and economical sensor with the shorter length has high sensitivity, satisfactory repeatability, and favorable stability. The sensitivity climbs with the increase in refractive index of the measured liquid, which is 204 pm/mm for pure water, 265.8 pm/mm for 10% glycerin solution, and 352.5 pm/mm for 25% glycerin solution. The proposed sensor can be standardized in certain application circumstances to achieve accurate liquid level monitoring.

Características de la glicerina obtenida del proceso de la reacción del metóxido de sodio en la producción del Biodiesel

Biodiesel is one of the alternative sources of energy obtained from the edible oils used in different types of kitchens as a renewable resource. The by-product derived from the reaction process transesterification in the production of biodiesel is glycerin the aqueous glycerin solution is filtered to remove the impurities and then neutralized with 1N NaOH. The objective of this work was to identify the characteristics of this glycerin and its applications and future use, the characterization made of this by-product from which it was collected. liters in amber bottles, the pH range between 6 and 7, density 1.24 g / l, viscosity .897 pascal sec., it is possible to recover methanol to a purity of 58% by weight, glycerin is used in many products of consumption, has a low toxicity, its properties are stability and compatibility towards other chemical compounds. The applications of this by-product are the manufacture of liquid soap, degreaser, floor cleaning, it is a non-irritating, biodegradable and recyclable compound.

THE PROPERTIES OF THE CONIDIA OF STRAINS OF THE ACTINOMYCETE STREPTOMYCES LUCENSIS AND STREPTOMYCES VIOLACEUS DURING STORAGE AT LOW TEMPERATURES

Collection cultures of actinomycetes are mainly stored in a dried state on adsorbents. Practiced low-temperature storage of actinomycetes at minus 70°C. The article presents the results of investigations of the properties of the conidia of strains of the actinomycete Streptomyces lucensis VKPM Ac–1743 and Streptomyces violaceus VKPM Ac–1734 is in the process of storage at minus 12°C and minus 18°C in glycerin solution and in 0,9 % aqueous sodium chloride solution. It was found that the inhibitory activity in the native solution for the studied strains stored in the glycerin solution at minus 12°C and plus 4°C, as a result of their subsequent cultivation on the starch hydrolyzate for 120 h is at the level of (450 ± 10) IE/cm3. The indicator for crops stored at minus 18°C was higher (560 ± 10) IE/cm3. Low-temperature storage of conidia in saline solution is less effective. Pigmentation is more active in the cultivation of strains stored at minus 18°C.

New Method To Reduce Residual Oil Saturation by Polymer Flooding

Summary Six coreflood experiments were conducted to investigate the effect of hydrolyzed-polyacrylamide (HPAM) polymer solutions on the residual oil saturation (ROS) in Bentheimer-sandstone cores. All six cores were first saturated with brine and then flooded in the following sequence: oil to zero water cut, brine to zero oil cut, glycerin solution to zero oil cut, polymer in low-salinity brine to zero oil cut, and finally polymer in high-salinity brine to zero oil cut. The first polymer solution had approximately the same viscosity as the glycerin solution. The first polymer flood was designed to maximize the effect of viscoelasticity on the ROS by flooding the cores at a high Deborah number (NDe), and, as expected, resulted in a lower ROS. The second polymer flood in high-salinity brine had approximately the same viscosity, but a much lower relaxation time, and the flood had a much lower NDe. Unexpectedly, there was a further substantial reduction in ROS during the second polymer flood. The lowest ROS after the second polymer flood was only 0.07. This is a truly remarkable result, considering that there was no reduction in interfacial tension (IFT), the capillary numbers were maintained below the critical capillary number for Bentheimer sandstone, and the viscosities of both polymer solutions were equal to or less than that of the glycerin solution.