function par = v1_gaslift_parameters()
par=[];
%% Viscosity (Liquid)
par.my=0.364e-3; %Read from olga values at 100 C
%% Density Liquid [kg/m^3]
par.rho_L=760; %Read from Olga at values at 100 C

%% Temperature riser
%par.T_r=373; %[K] avg temperature in the middle of the tubing olga
par.T_r=369.4; %[K]temperature at top of the tubing olga
%% Gas molar weight in top of riser	[kg/mol]
par.M_G_r_t=0.0167;
%% Gas molar weight in top of riser	[kg/mol]
par.M_G_r=0.0167;
%% Gravity
par.g=9.81;
%% Universal Gas constant
par.R=8.314;  % [J/Kmol]

%% Temperature annulus
par.T_a=348; %Temperature in the OLGA gas source
%% Gas molar weight annulus
par.M_G_a=0.01631;  %[kg/mol]

%% Calculating good values for valve constats K_a and K_r
%    par.K_a= 0.43*1.655e-3; %Out of annulus into tubing, Increasing gives: unstable, higher BH but no big change
%    par.K_s = 8e-5;     %Into annulus,
%    par.K_r= 0.49*3.8353e-3;  %Prod Choke, Increasing gives: Unstable, lower BH

par.PI = 2.47e-6;%4e-6;  %Productivity Index

%% OLGA ANNULUS VOLUMES CALCULATION:
%pipe1=pi*((0.2/2)^2)*10;
%pipe_1A=pi*((0.2/2)^2)*20;
%pipe_1B=pi*((0.2/2)^2)*40;
%pipe_2=pi*((0.2/2)^2)*2028;
%pipe_3=pi*((0.05/2)^2)*10;
%Volume_annulus=pipe1+pipe_1A+pipe_1B+pipe_2+pipe_3;
Volume_annulus=2048*pi*((0.2/2)^2);
par.V_a=Volume_annulus;
%par.L_a=10+20+40+2028+10;
par.L_a=2048;

%% OLGA TUBING VOLUMES CALCULATION
pipe3=pi*((0.124/2)^2)*1900;
pipe2=pi*((0.124/2)^2)*148;
pipe1=pi*((0.124/2)^2)*25;
Volume_tubing=pipe1+pipe2+pipe3;
%Volume_tubing=pipe2+pipe3;
par.V_t=Volume_tubing;
par.V_r=Volume_tubing;
par.r_r=0.124/2;
par.L_r=2048;%vertical
par.L_h = 25; %Horizontal

%% Roughness of well
par.ew = 4.5e-5;

%% Roughness of horizontal pipe
par.ep = 3e-5;

%% OLGA BOTTOM HOLE VOLUMES CALCULATION
par.L_bh=75;%100;
par.S_bh=pi*((0.2/2)^2);
par.V_bh = par.L_bh*par.S_bh;
par.D_w = 0.124;
par.D_b = 0.2;

%% Steady State Values From OLGA
z1=0.25;
w_res_in=12.7841; % increasing gives: decrease (want lower pressure drop from friction) vil ha høyere pbh
w_g_a_in=0.8;
w_mix_out=w_res_in+w_g_a_in;
Pbh=108.243e5;
Pab=103.165e5;
Ptb=102.847e5;
Ptt=28.3354e5;
Pat=92.2582e5;

x1 = par.M_G_a*par.V_a*Pat/(par.R*par.T_a);
Pab= Pat + (x1*par.g*par.L_a/par.V_a);

rho_G_ab=Pab*par.M_G_a/(par.R*par.T_a);
P_t_avg=(Ptt+Ptb)/2;
rho_G_t_avg=P_t_avg*par.M_G_r_t/(par.R*par.T_r);
alpha_L_avg=rho_G_t_avg*w_res_in/(rho_G_t_avg*w_res_in + par.rho_L*w_g_a_in);
rho_mix_avg=par.rho_L*alpha_L_avg + rho_G_t_avg*(1-alpha_L_avg);

%% ************  Calculating Friction of Riser **********
Usl_av=w_res_in/(par.rho_L*pi*(par.r_r^2)); 
Usg_av= (w_g_a_in)/(rho_G_t_avg*pi*(par.r_r^2));

U_M_av=Usl_av+Usg_av;
Re=(2*rho_mix_avg*U_M_av*par.r_r)/par.my;

%% Darcy Friction Factor
temp = -1.8*log10((par.ew/par.D_w/3.7)^1.11+6.9/Re);
lambda=(1/temp)^2;
%lambda=0.0056+(0.5*(Re^(-0.32)));
F_riser=alpha_L_avg*(lambda*rho_mix_avg*(U_M_av^2)*(par.L_r+par.L_h))/(4*par.r_r);
%%

Ptb=Ptt+F_riser+rho_mix_avg*par.g*par.L_r;

rho_G_tb=Ptb*par.M_G_r/(par.R*par.T_r);
alpha_L_b=rho_G_tb*w_res_in/(rho_G_tb*w_res_in + par.rho_L*w_g_a_in);
alpha_L_t=2*alpha_L_avg -alpha_L_b;
rho_G_tt=Ptt*par.M_G_r/(par.R*par.T_r);
rho_top=par.rho_L*alpha_L_t + rho_G_tt*(1-alpha_L_t);

par.CD=0.84;
par.D_v=0.025;
par.A_v=pi*(par.D_v/2)^2;

par.D_c=0.07;
par.A_c=pi*(par.D_c/2)^2;

%hvis k1 blir større må k2 bli større. deltak2=0.01 tilater deltak1=0.0?
k1=0.68;   % Annulus
k2=1;  % Tubing
%par.K_a= k1*1.074719873340e-3;
par.K_a= k1*w_g_a_in/sqrt(rho_G_ab*(Pab-Ptb)); %Out of annulus into tubing, Increasing gives: unstable,lower annnulus pressure ,higher BH but no big change
par.K_s = 8e-5;     %Into annulus,


par.K_r= k2*w_mix_out/(z1*sqrt(rho_top*(Ptt-15e5)));   %Prod Choke, Increasing gives: Unstable, lower BH



%PI=12.7841/((1e5*(160-108.243)));
%M_g_a=58.1542*par.R*par.T_a/103.165e5

end