Wet electric heating process

A method for heating a subterranean formation having hydrocarbons, the method comprising:

• (a) providing at least a first conductor and a second conductor, wherein
• (i) the first and second conductor are spaced-apart in the formation, and
• (ii) there is electrical connectivity between the first and second conductors;
• (b) establishing at least a first electrode zone and a second electrode zone, each electrode zone having electrolyte, around the first and second conductors, respectively, and thereby creating a target region, having a center point, between opposing faces of the first and second electrode zones, wherein each electrode zone has an average effective radius that is at least about 2.3% of the distance between the centerline of the first conductor and the centerline of the second conductor;
• and
• (c) establishing at least about a 50% difference in electrical conductivity between the target region and independently each of the first and second electrode zones, wherein the electrical conductivity of the first and second electrode zones are each independently greater than an initial electrical conductivity of the target region, wherein the initial electrical conductivity of the target region is the average electrical conductivity, prior to applying an electric potential difference between the first and second electrode zones, in a substantially spherical portion centered around the center point of the target region, the substantially spherical portion of the target region having a radius of about 15% of the average spacing between opposing faces of the first and second electrode zones;
• so that at about 10% of a predetermined time interval over which an electric potential difference is continuously applied between the first and second electrode zones, there is at most about 60% deviation between the maximum and minimum values for a gamma ratio, Γ, generated within the target region, wherein %Γ deviation is calculated as:
• %ΓDeviation=[(Γmax−Γmin)/Γmax]×100
• where
• %Γ Deviation is the deviation of Γ values determined in a target region divided into n imaginary layers, wherein each imaginary layer has a highest temperature Tn at a point radially located a distance x from the first conductor and the thickness of the imaginary layer is determined by the length of an imaginary line parallel to and a radial distance x from the first conductor, wherein the temperature values along the imaginary line fall in a range Tn≧T≧0.85Tn, as measured at about the initial 10% of the continuous electric heating time interval;
• n is greater than or equal to 2;
• Γmax is the highest Γ of the n respective Γ values determined in the n layers at about the initial 10% of the continuous electric heating time interval;
• Γmin is the lowest Γ of the n respective Γ values determined in the n layers at about the initial 10% of the continuous electric heating time interval;
• and
• Γ is a ratio of a rate of temperature increase for the portion of the target region having the highest temperature value versus a rate of temperature increase at an effective mid-point between the first and second electrode zones.

A method for heating a subterranean formation having hydrocarbons, the method comprising:

• (a) providing at least a first conductor and a second conductor, wherein
• (i) the first and second conductor are spaced-apart in the formation, and
• (ii) there is electrical connectivity between the first and second conductors;
• (b) establishing at least a first electrode zone and a second electrode zone, each electrode zone having electrolyte, around the first and second conductors, respectively, and thereby creating a target region, having a center point, between opposing faces of the first and second electrode zones, wherein each electrode zone has an average effective radius that is at least about 2.3% of the distance between the centerline of the first conductor and the centerline of the second conductor;
• and
• (c) establishing at least about a 50% difference in electrical conductivity between the target region and independently each of the first and second electrode zones, wherein the electrical conductivity of the first and second electrode zones are each independently greater than the initial electrical conductivity of the target region, wherein the initial electrical conductivity of the target region is the average electrical conductivity, prior to applying an electric potential difference between the first and second electrode zones, in a substantially spherical portion centered around the center point of the target region, the substantially spherical portion of the target region having a radius of about 15% of the average spacing between the opposing faces of the first and second electrode zones;
• so that at about 10% of a predetermined time interval over which an electric potential difference is continuously applied between the first and second electrode zones, there is at most about 35% deviation between the highest and lowest maximum temperatures, Tmax, generated within the target region, wherein %Tmax deviation is calculated as:
• %TmaxDeviation=[(Tmax−high−Tmax−low)/Tmax−high]×100
• where
• %Tmax Deviation is the deviation of Tmax values determined in a target region divided into n imaginary layers, wherein each imaginary layer has a highest temperature Tn at a point radially located a distance x from the first conductor and the thickness of the imaginary layer is determined by the length of an imaginary line parallel to and a radial distance x from the first conductor, wherein the temperature values along the imaginary line fall in a range Tn≧T≧0.85Tn, as measured at about the initial 10% of a continuous electric heating time interval;
• n is greater than or equal to 2;
• Tmax−high is the highest Tmax of the n respective Tmax values determined in the n layers at about the initial 10% of the continuous electric heating time interval;
• and
• Tmax−low is the lowest Tmax of the n respective Tmax values determined in the n layers at about the initial 10% of the continuous electric heating time interval.