Superiority of Superheated Steam Flooding in Development of High Water-Cut Heavy Oil Reservoir

Abstract

The dryness of superheated steam is 100% and it exists in the form of pure steam whose properties are like ideal gas. When the steam has a large degree of superheat, it may take a relatively long time to cool, during which time the steam is releasing very little energy and transmitted long distances. The heating radius of superheated steam in the formation is 5-10m larger than saturated steam. In the heating area of superheated steam, the comprehensive effects by superheated steam (crude oil viscosity reduction, improved flow environment, changes in rock wettability and improved oil displacement efficiency, etc.) is much higher than that of saturated steam. Superheated steam stimulation in Kenkyak high water cut heavy oil reservoir pilot test results showed that the average daily oil production of single well by superheated steam stimulation was 2-4 times than that of saturated steam stimulation. Superheated steam is more effective to heat water-invaded oil reservoir than saturated steam.

Exploitation of heavy oil by supercritical CO2: Effect analysis of supercritical CO2 on H2O at superheated state in integral joint tubing and annuli

“…When superheated steam flows from well‐head to well‐bottom, it may undergo a phase change to wet steam due to heat loss . If that happens, the two‐phase flow model proposed by Xu et al .…”

“…The temperature difference between SHS and saturated steam under the same pressure is defined as the superheat degree . Superheated steam has been proved to be effective in improving formation permeability, hydrothermal cracking efficiency, increasing heated radius, and so forth . Moreover, both laboratory tests and real‐life practice reveal that CO 2 has the oil‐displacement mechanisms of dissolution and viscosity reduction, swelling action, lower interfacial tension, and steam absorption profile adjustment .…”