Definition

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

Application

assess current production distribution
assess current distribution of recovery against expectations
assess current status and trends of recovery against expectations
assess current status and trends of reservoir depletion against expectations
assess 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

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

It 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 Map

Background = STOIIP & Structure

Bubbles = q_o, q_g , q_w, q_inj

Number = VRR, P_e

Production Distribution Overview

(1)	$\begin{array}{l}\displaystyle {\rm VRR_{cum}} = \frac{B_w \, Q_{WI}}{B_w \, Q_W + B_o \, Q_O + B_g Q_G - B_g R_s Q_O}\end{array}$

(2)	$\begin{array}{l}\displaystyle {\rm VRR_{inst}} = \frac{B_w \, q_{WI}}{B_w \, q_W + B_o \, q_O + B_g (q_G - R_s Q_O)}\end{array}$

2

Recovery Map

Background = STOIIP & Structure

Bubbles = Q_o, Q_g , Q_w, Q_inj

Number = VRR, P_e

Recovery Distribution Overview

(3)	$\begin{array}{l}\displaystyle {\rm RF} = \frac{Q_o}{V_{STOIIP}}\end{array}$

3

Production History Graphs

Left Axis = q_o, q_g , q_w, q_inj,

Rigth Axis = Y_w, Y_g, P_e , N_p, N_inj

Hor Axis = Elapsed Time

Production History Overview

(4)	$\begin{array}{l}\displaystyle {\rm Y_w} = \frac{q_w}{q_{lis}}\end{array}$

(5)	$\begin{array}{l}\displaystyle {\rm Y_g} = \frac{q_g}{q_o}\end{array}$

(6)	$\begin{array}{l}\displaystyle q_{liq} = q_o + q_w\end{array}$

4

Decline Curve Analysis

Left Axis = q_o1, q_liq₁, q_inj1,

Rigth Axis = Y_w, Y_g, VRR, P_e

Hor Axis = Elapsed Time

Production Forecast

5

Recovery Diagnostic

Left Axis = q_o1, q_liq₁, q_inj1

Rigth Axis =Y_w, Y_g, VRR, P_e, P_em

Hor Axis = RF

Estimate recovery efficiency and pressure decline

6

Watercut Diagnostic

Left Axis = Y_w, Y_wm

Hor Axis = q_liq

Check for water balance and thief water production

(7)	$\begin{array}{l}\displaystyle {\rm Y_w} = \frac{1}{1 + \frac{K_{ro}}{K_{rw}} \cdot \frac{\mu_w}{\mu_o} \cdot \frac{B_w}{B_o}}\end{array}$

7

GOR Diagnostic

Left Axis = Y_g, Y_gm

Hor Axis =q_o

Check for gas balance and thief gas production

8

Injection Efficiency Diagnostics

Left Axis = PIR , PIR_m

Hor Axis = Y_w

Evaluate WI efficiency

(8)	$\begin{array}{l}\displaystyle {\rm PIR} = \frac{Q_o}{Q_i}\end{array}$

(9)	$\begin{array}{l}\displaystyle {\rm PIR_m} = { \frac{1}{VRR} }*{ \frac{1-Y_w}{ Y_w + (1-Y_w) [ \frac{B_o}{B_w} - \frac{B_g}{B_w}(Y_g - R_s) ] } }\end{array}$

9

Well Performance Analysis

Left Axis = P_{wf_IPR} , P_{wf_VLP}

Hor Axis = q_o

Check for the optimal production/injection target

(10)	$\begin{array}{l}\displaystyle P_{wf} = P_e - \frac{1}{J_{PI}} q_o\end{array}$

10

Productivity Index Diagnostic

Left Axis = J_PI, J_PIm

Hor Axis = dP = P_wf - P_e

Check for PI dynamics

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

(12)	$\begin{array}{l}\displaystyle {\rm J_{PIm} } = \frac{q_o}{P_e - P_{wf}}\end{array}$

PIR equation deduction

(13)	$\begin{array}{l}\displaystyle Y_w=\frac{q_q}{q_w + q_o} \rightarrow \frac{q_o}{q_w} = \frac{1-Y_w}{Y_w}\end{array}$

(14)	$\begin{array}{l}\displaystyle PIR=\frac{q_o}{q_i}\end{array}$

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

Diagnostic

Expand

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