SAGD dilation startup and its applications in a shallow super heavy-oil reservoir in xinjiang oil field, China

SAGD dilation startup and its applications in a shallow super heavy-oil reservoir in xinjiang oil field, China

Crude oil

Deformation

Petroleum industry

Rock mechanics

Oil sands

Shear stress

Heavy oil production

Oil wells

Petroleum reservoir engineering

Petroleum reservoirs

Numerical models

Rocks

Steam

Porosity

Microcracks

This paper presents a detailed study of the SAGD dilation start-up technology, including the fundamental mechanism, numerical model, field operations, and well performance in PetroChina's Karamay "super" heavy-oil reservoir. Rock dilation refers to a rock deformation phenomenon in which the volume of the porous rock increases when the porous rock undergoes shear stress or an increase in pore pressure. The dilation process creates additional porosity inside the rock and thus the increased permeability and fluid mobility. These newly created porosities or microcracks provide fluid pathways for the injection of reservoir stimulants, such as steam, solvent, and other chemical viscosity reducers. The theoretical basis of the dilation start-up technology, including the experimental and field evidences of dilation in unconsolidated oil sands are presented. A numerical model for simulating the dilation start-up process is also presented. The rock deformation and failure parameters were obtained through laboratory triaxial tests on in situ rock cores and the in-situ stress conditions were measured using minifrac tests. Field examples will be presented to illustrate field operations and the impact of the dilation startup on SAGD steam circulation and oil-production rate. Since 2013, this technology has been applied to more than 60 SAGD well pairs and excellent field results have been generated in terms of reduced steam use, shortened steam circulation time, and increased initial oil production. 2020 ARMA, American Rock Mechanics Association

54th U.S. Rock Mechanics/Geomechanics Symposium, June 28, 2020 - July 1, 2020

2020

Sun, X.

Qian, G.

Xu, B.

Li, B.

Du, J.

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