Patent ID: 8645069

Claim:
A method for determining saturated steam dryness in a well comprising: injecting steam having a known wellhead steam dryness Q s into the well at a wellhead injection pressure P s , determining a total system pressure P m at any selected location (m) within a wellbore of the well, adding a non-condensable gas into the steam being injected, determining a partial steam pressure P steam,s at a condensation temperature T s in a wellhead of the well (s), determining a partial steam pressure P steam,m at a condensation temperature T m at the selected location (m) in the wellbore, and determining the steam dryness at the selected location (m) by formula: Q m = Q s · z gas , m z gas , s · z steam , s z steam , m · P steam , m P steam , s · P s - P steam , s P m - P steam , m where Q s is the known wellhead steam dryness, P s is the wellhead injection pressure, P m is the total system pressure at the selected location (m) in the wellbore, P steam,s is the partial steam pressure at the wellhead (s), P steam,m is the partial steam pressure at the selected location (m) in the wellbore, Z steam,s is a compressibility of steam in the wellhead (s), Z steam,m is a compressibility of steam at the selected location (m) in the wellbore, Z gas,s is a compressability of the non-condensable gas in the wellhead (s), Z gas,m is a compressability of the non-condensable gas at the selected location (m) in the wellbore.