An improved algorithm for unknown flow rate history reconstruction with the Haar wavelet transform. (2018)

• Record Type: Journal Article
• Authors: Wang, Fuyong
• Is Part Of: International journal of oil, gas and coal technology. Volume 19:Number 1(2018)
• Page Start: 59
• Page End: 82
• Publication Date: 2018
• Subjects: well test -- pressure-transient analysis -- production history -- flow rate -- transient pressure -- wavelet transform -- Haar wavelet -- permanent down-hole gauge -- PDG; Petroleum as fuel -- Periodicals; Gas as fuel -- Periodicals; Coal -- Periodicals; Biomass energy -- Periodicals; Hydrogen as fuel -- Periodicals; 662.6
• Languages: English
• ISSNs: 1753-3309

Abstract

Flow rate history is the key information for reservoir surveillance and management, but it is not always available in practice due to expensive and unstable metering devices. This paper proposes an improved algorithm of reconstructing flow rate history from down-hole transient pressure data with wavelet transform (WT). The Haar wavelet can effectively identify flow events and distinguish pressure drawdowns from buildups, and the amplitude of WT coefficients of flow event is proportional to the flow rate change. The effects of data noise, wellbore storage and skin on flow event identification were investigated. The improved algorithm can reconstruct the flow rate history when the initial flow rate is unknown, and this improved algorithm was demonstrated with synthetic case studies and field application. [Received: November 25, 2015; Accepted: July 17, 2016]