Definition

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

Application

understand the current status and trends of reservoir depletion against expectations
understand the current status and trends of water flood efficiency against expectations
quantitatively compare performance of different wells or different groups of wells
identify and prioritize redevelopment opportunities

Technology

PRIME analysis is built around production data against material balance and require current FDP volumetrics, PVT and SCAL models.

PRIME includes well-by-well diagnostics and gross field diagnostics, but may be extended to sector-by-sector diagnostics.

Metrics

PRIME includes the following metrics:

	Metric name	Diagnostic plots	Objectives
1	Production History	q_o, q_g , q_w, q_inj, Y_w, GOR, P_e , N_p, N_inj vs time	Production History Overview
1	Decline Curve Analysis	q_o1, q_liq₁, q_inj1,Y_w, GOR, VRR, P_e vs time	Production forecast
2	Recovery Diagnostic	q_o1, q_liq₁, q_inj1, Y_w, GOR, VRR + P_e vs RF	Estimate recovery efficiency
3	Pressure Diagnostic	VRR, P_e , P_{e_MatBal}vs RF	Estimate pressure balance against material balance
4	Watercut Diagnostic	Yw vs Y_{w_MatBal} + Yw vs q_t	Check for water balance and thief water production
5	GOR Diagnostic	GOR vs GOR_MatBal + GOR vs q_t	Check for gas balance and thief gas production
6	Injection Efficiency Diagnostics	PIR & PIR_MatBal vs Yw	Evaluate WI efficiency
7	Well Performance Analysis	IPR P_wf , VLP P_wfvs q	Check for the optimal production/injection target
8	Productivity Index Diagnostic	J_PI vs dP	Check for PI dynamics

Models

VRR vs RF

(1)	$\begin{array}{l}\displaystyle VRR=\frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_O + B_g (q_G - R_s q_O)}=\frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_G - B_g (Y_g - R_s) q_O}\end{array}$

PIR vs Yw

(2)	$\begin{array}{l}\displaystyle {PIR=\frac{Q_o}{Q_i};} {\qquad} {\gamma}=\frac{Q_w}{Q_w + Q_o} {\quad \Rightarrow \quad} \frac{Q_w+Q_o}{Q_w}=\frac{1}{\gamma} {\quad \Rightarrow \quad} \frac{Q_o}{Q_w}={\frac{1}{\gamma}-1} {\quad \Rightarrow \quad} \frac{Q_o}{Q_w}=\frac{1-\gamma}{\gamma}\end{array}$

IPR_w vs Pe

(3)	$\begin{array}{l}\displaystyle PI=\frac{Q}{P_e - P_{wf}} {\quad \Rightarrow \quad} P_{wf}=P_e - \frac{1}{PI}Q\end{array}$

Вывод уравнения PIR

$\begin{array}{l}\displaystyle Q_w=\frac{\gamma}{1-\gamma}{Q_o}\end{array}$

$\begin{array}{l}\displaystyle VRR=\frac{B_w Q_i}{B_w Q_w + [ B_o - B_g (GOR - R_s ) ] Q_o}=\frac{B_w Q_i}{ [ B_w \frac{\gamma}{1-\gamma} + [ B_o - B_g (GOR - R_s ) ] ] Q_o }\end{array}$

$\begin{array}{l}\displaystyle PIR=\frac{Q_o}{Q_i}={ \frac{1}{VRR} }*{ \frac{1}{ \frac{\gamma}{1-\gamma} + [ \frac{B_o}{B_w} - \frac{B_g}{B_w}(GOR - R_s) ] } }\end{array}$

$\begin{array}{l}\displaystyle PIR=\frac{Q_o}{Q_i}={ \frac{1}{VRR} }*{ \frac{1-\gamma}{ \gamma + [ \frac{B_o}{B_w} - \frac{B_g}{B_w}(GOR - R_s) ] } }\end{array}$

Sample Case


Fig. 1. Decline Curve Analysis	Fig. 2. Recovery Diagnostic	Fig. 3. Pressure Diagnostic

Fig. 4. Watercut Diagnostic	Fig. 5. GOR Diagnostic	Fig. 6. Injection Efficiency Diagnostics

Fig. 7. Well Performance Analysis	Fig. 8. Productivity Index Diagnostic

Page tree

PRIME – Primary Production Analysis