In-situ generated proppant for hydraulic fracturing

Abstract

The invention discloses an in-situ generated proppant for hydraulic fracturing. When a feed solution of the proppant and a fracturing fluid are injected into an artificial fracture together, small liquid beads formed by the feed solution of the proppant in the pumping process are dispersed in the fracturing fluid, the small liquid beads are carried into the artificial fracture by the fracturing fluid, and the small liquid beads undergo a curing reaction in the fracture to form the spherical granular proppant. The feed solution of the proppant comprises the following components: curable resin,a diluent, a curing agent and a pH regulator, wherein the curable resin is one or a mixture of at least two selected from thermoplastic phenolic resin, thermoplastic urea resin and melamine-formaldehyde resin. A phase interface stabilizer is added into the fracturing fluid. The feed solution beads of the proppant are gradually cured in fracture to form solid particles with good sphericity and highstrength, the effects of supporting artificial fracture and maintaining a high flow guide channel are achieved, and the exploitation efficiency of oil and gas fields is improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploitation, in particular to an in-situ generated proppant for hydraulic fracturing. Background technique [0002] Hydraulic fracturing technology, as the main measure for increasing production of oil and gas wells and increasing injection of water wells, has been widely used in the development of low-permeability / ultra-low-permeability oil and gas fields, and is one of the most important measures to stabilize production in oil and gas fields. The process of hydraulic fracturing is to pump high-viscosity pre-fluid into the target reservoir, and form extended fractures in the formation with a high pressure exceeding the fracture pressure of the formation; then inject sand-carrying fluid mixed with proppant into the formed fractures, so that The proppant is spread in the fracture; finally, the sand-carrying fluid is broken and viscous-reduced into a low-viscosity fluid, which flows to the well...

AI Technical Summary

Problems solved by technology

[0005] 1) If the fracturing fluid is not completely broken and flowed back, it will seriously damage the conductivity of the formed artificial fractures and reduce the matrix permeability near the fractures;

[0006] 2) In the face of high-temperature deep wells, in order to maintain the sand-carrying ability of the fracturing fluid at high temperatures, the concentration of additives such as guar gum and cross-linking agent is increased, resulting in a further increase in residue content, further increase in friction, and more gel breaking. , flowback and other issues;

[0007] 3) For the secondary and tertiary branch fractures with small width, it is difficult for solid proppant to enter to form effective support;

[0008] 4) Since the injection of solid proppant will cause certain wear and tear on the pipeline and wellbore, at the same time, the sand filling fracturing process is complicated, and the high displacement and high pump pressure accompanied by high sand filling have high requirements on the wellhead, construction equipment and construction string. Improper control in the process of adding sand will also cause sand plugging, which is a potential large construction risk and personnel safety risk

These problems may often lead to a great reduction in the conductivity of the induced fractures, so the fracture permeability measured by the well test after fracturing can often only reach one tenth or even one percent of the laboratory

Images