de =  6.000 ;              // Electrode Spacing
re =  0.3048 /2 * Cos[0] ; // Radius of the electrode
le = Sqrt[3]*de/2 ;        // Offset Spacing
rn = de/4 ;                // Near wellbore Radius

p0 = 0.2 /  5 ;

/* defining the points */

x = re;
y =  0;
Point(1)  = {x,y,0,p0};

x = de-re;
y =  0;
Point(2)  = {x,y,0,p0};

x = de-re*Cos[Pi/3];
y =    re*Sin[Pi/3];
Point(3)  = {x,y,0,p0};

x = de/2 + re*Cos[Pi/3];
y =   le - re*Sin[Pi/3];
Point(4)  = {x,y,0,p0};

x = de/2 - re*Cos[Pi/3];
y =   le - re*Sin[Pi/3];
Point(5)  = {x,y,0,p0};

x = re*Cos[Pi/3];
y = re*Sin[Pi/3];
Point(6)  = {x,y,0,p0};

x = 0;
y = 0;
Point(7)  = {x,y,0,p0};

x = de;
y = 0;
Point(8)  = {x,y,0,p0};

x = de/2;
y = le;
Point(9)  = {x,y,0,p0};

x = rn;
y = 0;
Point(10)  = {x,y,0,p0};

x = rn*Cos[Pi/3];
y = rn*Sin[Pi/3];
Point(11)  = {x,y,0,p0};





/* defining the lines */

Line(1) = {1,10};
Line(2) = {10,2};
Line(3) = {3,4};
Line(4) = {5,11};
Line(5) = {11,6};

Circle(102) = {5, 9, 4};
Circle(103) = {3, 8, 2};
Circle(104) = {6, 7, 1};

Circle(105) = {11, 7, 10};

Line Loop(106) = {3, -102, 4, 105, 2, -103};
Line Loop(108) = {5, 104, 1, -105};

Plane Surface(107) = {106};
Plane Surface(109) = {108};

Physical Line(110) = {5, 4, 3, 2, 1};
Physical Line(111) = {104};
Physical Line(112) = {102};
Physical Line(113) = {103};
