An experimental investigation on the effect of grain size on oil-well sand production

Abstract

Sand production in oil wells is closely related to the mechanical behavior and petrographical properties of sandstones reservoir. Grain size is one of the main parameters controlling the phenomenon, which is studied in this paper. Large-scale hollow cylindrical synthetic samples with the same rock strength but different grain sizes were tested by an experimental setup in the laboratory. Different external grain size (D 50 <0.3 mm), the required confining stress for different sanding levels decreased with an increase in the grain size and for the samples with the coarser grains (D 50 stress for different sanding levels dramatically increased with an increase in the grain size. Those two second was bigger chunks in the slab form. In samples with large grains, plastic zones around hole were changed to a completely loose zone including interlocked individual grains or cluster of grains. In these samples after breakage of these interlocked zones sand was produced in the form of individual grains and clusters. Contrary to this, for samples with smaller grain size, shear bands were formed around the

Particulate Modeling of Sand Production Using Coupled DEM-LBM

“…He reported that the cavity enlargement decreases the sand initiation stress, whereas stronger samples show higher sand initiation stress. Similar parameters were studied by Fattahpour et al [2,3]. They recognized five distinct sand production stages in their experiments, including sand initiation, transient, semi-continuous, continuous, and catastrophic sand production.…”

“…It can be summarized as the separation and erosion of grain particles from the wellbore wall, along with the extraction of hydrocarbons. Redistribution of in-situ stress or the increased effective stress (in a depleting reservoir) leads to the failure of weak rock around the wellbore [2][3][4][5][6]. Consequently, some parts of the rock are disintegrated and may dislocate and enter the extraction well as a result of flowinduced hydrodynamic forces.…”

“…After that, each set of bonded models and unbonded particle assembly were subjected to 50 and 100 kPa isotropic stresses during the In the current biaxial studies, 2000 octagonal (regular eight-sided polygon) particles with relatively uniform sizes are generated. Compared to circular particles used in previous numerical studies, the particles' octagonal shape can mimic the increased interlocking of actual irregular-shaped sand particles as most of the grains in natural sandstones are angular [3]. On the other hand, the roundness of octagonal particles helps avoid induced anisotropy in the model [46].…”

Polyacrylamide hydrogel application in sand control with compressive strength testing

“…Sand production is one of the common problems in oil and gas production wells drilled in unconsolidated formations (Fattahpour et al 2012). The abrasive flow of sand grains inside the wells and production lines leads to undesirable consequences including erosion of downhole or wellhead equipment, clogging of downhole equipment, subsidence of formation rock, walls destruction, reduction in reservoir recovery, maintenance cost, and in severe cases even death of the well (Ikporo and Sylvester 2015;Isehunwa and Olanrewaju 2010;Pedersen et al 2017;Singh and van Petegem 2014).…”

Ureolytic activities of a urease-producing bacterium and purified urease enzyme in the anoxic condition: Implication for subseafloor sand production control by microbially induced carbonate precipitation (MICP)

“…Sand production has been a major obstacle for the successful exploitation of weakly consolidated /unconsolidated oil and gas reservoirs worldwide. It is reported that 70% of the global hydrocarbon reservoirs are susceptible to sand production (Fattahpour et al 2012). Typically, sand production is defined as sand particles in weakly consolidated subsea hydrocarbon-bearing sediments moving into the exploitation well along with the hydrocarbon and water flows, due to drilling and completion activities.…”