Delivery of particulate material below ground

摘要

A wellbore fluid comprises an aqueous carrier liquid, hydrophobic particulate material suspended therein and a gas to wet the surface of the particles and bind them together as agglomerates. The hydrophobic particulate material has a specified maximum volume median particle size d50 of not more than 200 micron, and/or a minimum surface area of at least 30 m2 per liter. Agglomerates of the particles contain gas and so have a bulk density lower than the density of the particles. This reduces the rate of settling. The fluid is particularly envisaged as a slickwater fracturing fluid in which the suspended particles are proppant. The small particle size and/or substantial surface area increases the amount of gas which can be retained within agglomerates and so enhances the buoyancy of the agglomerates. The end result is that a greater proportion of a hydraulic fracture is propped open.

主权项

1. A method of delivering particulate material below ground, comprising supplying, underground, a fluid composition comprising an aqueous carrier liquid with a hydrophobic particulate material suspended therein, the hydrophobic particulate material having a volume median particle size d50 of not more than 125 micron, determined as median diameter of spheres of equivalent volume, the fluid also comprising a gas wetting the surface of the particles and binding the particles together such that agglomerates of the particulate material held together by the gas are present below ground, wherein the agglomerates of the particulate material have a density equal to or less than 1.4 g/ml.