Definition

Primary Production Analysis is the specific workflow and report template on Primary Well & Reservoir Performance Indicators.

Application

• Assess current production performance
  
  
  • current distribution of recovery against expectations
    
    
  • current status and trends of recovery against expectations
    
    
  • current status and trends of reservoir depletion against expectations
     
  • current status and trends of water flood efficiency against expectations
    
    
  • compare performance of different wells or different groups of wells 
    
    
• Identify and prioritize surveillance opportunities
  
  
• Identify and prioritize redevelopment opportunities
  
  

Technology

Primary Production Analysis is built around production data against material balance and require current FDP volumetrics, PVT and SCAL models. 

The PRIME workflow has certain specifics for oil producers, water injectors, gas injectors and field/sector analysis. 

The PRIME analysis is

• fast-track
  
  
• based on the most robust input data
  
  
• does not involve full-field 3D dynamic modelling and associtated assumptions

Obviously, PRIME does not pretend to predict pressure and reserves distribution as 3D dynamic model does.

It only provides hints for misperoforming wells and sectors which need a further focus.

{\rm VRR_{cum}} = \frac{B_w \, Q_{WI}}{B_w \, Q_W + B_o \, Q_O + B_g Q_G - B_g R_s Q_O}

{\rm VRR_{cur}} = \frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_O + B_g (q_G - R_s Q_O)}

{\rm RF} = \frac{Q_O}{V_{STOIIP}}

{\rm Y_w} = \frac{q_W}{q_{LIQ}}

{\rm Y_{wm}} = \frac{1}{1 + \frac{K_{ro}}{K_{rw}} \cdot \frac{ \mu_w}{\mu_o}  \cdot \frac{B_w}{B_o} }

s_w = \frac{Q_o \, B_o}{V_\phi}

{\rm GOR} = \frac{q_g}{q_o}

{\rm GOR_m} = R_s +  \frac{k_{rg}}{k_{ro}} 
\cdot \frac{\mu_o}{\mu_g} 
\cdot \frac{B_o }{B_g}

q_{LIQ} = q_O + q_W

{\rm PIR} = \frac{Q_O}{Q_{WI}}

{\rm PIR_m} = { \frac{1}{VRR} } \cdot { \frac{1-Y_w}{ Y_w + (1-Y_w) \bigg[ \frac{B_o}{B_w} - \frac{B_g}{B_w}(GOR - R_s) \bigg] } }

{\rm J_{O}} = \frac{q_O}{P_e - P_{wf}} {\quad \Rightarrow \quad} P_{wf} = P_e - \frac{1}{J_O} q_O

{\rm J_t} = \frac{q_t}{P_e - P_{wf}}

{\rm J_{tm} } = \frac{2 \pi \sigma}{\ln \frac{r_e}{r_w} +0.5 + S} 

{\rm j_t} = \frac{q_t}{h \cdot (P_e - P_{wf})}

{\rm j_{tm} } = \frac{2 \pi <k/\mu>}{\ln \frac{r_e}{r_w} +0.5 + S} 

VRR = \frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_O + B_g \, [ q_G - R_s \, q_O] } =  \frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_O + B_g \, [ GOR - R_s] q_O } = \frac{B_w \, q_{WI}}{B_w \, q_W + [ B_o  + B_g \, ( GOR - R_s) ] \, q_O }

VRR = \frac{q_{WI}}{q_W + \bigg[ \frac{B_o}{B_w}  + \frac{B_g}{B_w} \, ( GOR - R_s) \bigg] \, q_O }

Y_w=\frac{q_W}{q_W + q_O} \rightarrow \frac{q_O}{q_W} = \frac{1-Y_w}{Y_w} \rightarrow q_W =  \frac{Y_w}{1-Y_w} \, q_O

VRR =  \frac{q_{WI}}{q_O} \cdot \frac{1}{\frac{Y_w}{1-Y_w}  + \bigg[ \frac{B_o}{B_w}  + \frac{B_g}{B_w} \, ( GOR - R_s) \bigg] } =
\frac{q_{WI}}{q_O} \cdot \frac{1-Y_w}{Y_w  + (1-Y_w) \, \bigg[ \frac{B_o}{B_w}  + \frac{B_g}{B_w} \, ( GOR - R_s) \bigg] }

PIR=\frac{q_W}{q_{WI}} = \frac{1}{VRR} \cdot \frac{1-Y_w}{Y_w  + (1-Y_w) \, \bigg[ \frac{B_o}{B_w}  + \frac{B_g}{B_w} \, ( GOR - R_s) \bigg] }

 ›   PRIME Diagnostics

Sample Case 1 – Waterflood Sector Analysis

Fig. 1.1. Production History Map	Fig. 1.2. Recovery Map
Fig. 2.1. Cross-section & PLT, permeability, GOC, OWC	Fig. 2.2. Cross-section & PLT, STOIIP, GOC, OWC
Fig. 3.1. Production History Graphs	Fig. 3.2. Production Forecasts
Fig. 4.1. Recovery History	Fig. 4.2. Recovery Forecasts
Fig. 5.1. WOR Diagnostic	Fig. 5.2. GOR Diagnostic
Fig. 6.1. Specific Productivity Index Diagnostic	Fig. 6.2. Specific Injectivity Index Diagnostic
Fig. 7. Injection Efficiency Diagnostics

Sample Case 2 – Oil Producer Analysis

Sample Case 3 – Water Injector Analysis