Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.


Total produced or injected flowrate of all fluids across the well-reservoir contact with the volumes measured at the sandface temperature and pressure conditions.

Usually abbreviated as 

LaTeX Math Inline
bodyq_t
 or
LaTeX Math Inline
bodyqB
 (with the latter does not imply a product) or specifically
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_t
 for production and 
LaTeX Math Inline
body--uriencoded--q%5e%7B\downarrow%7D_t
 for injection.

The concept applies both to producing and injecting wells.

The main purpose of describing the intakes and offtakes in terms of the Total sandface flowrate 

LaTeX Math Inline
bodyq_t
 is that it measures the actual flowing volumes in porous formations and as such directly relate to reservoir pressure.


For volatile oil fluid model the total sandface flowrate is related to surface flowrates of fluid components as:

LaTeX Math Block
anchor

...

qt_VO
alignmentleft

...

q^{\uparrow}_t =

...

 q^{\uparrow}_w + q^{\uparrow}_o + q^{\uparrow}_g = B_w \, 

...

q^{\uparrow}_W

...

 + 

...

(B_o - R_s \, B_g

...

) \, q^{\uparrow}_O + (B_g - R_v \, 

...

B_

...

o) \, q^{\uparrow}_G
LaTeX Math Block
anchorqt_VO
alignmentleft
q^{\downarrow}_t = q^{\downarrow}_w + q^{\downarrow}_g = B_w \, q^{\downarrow}_W + B_g \, q^{\downarrow}_G


where

LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_w
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_o
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_g

water sandface flowrate, oil sandface flowrategas sandface flowrate

LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_W
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_O
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_G

produced water surface flowrate, oil surface flowrategas surface flowrate

LaTeX Math Inline
body--uriencoded--q%5e%7B\downarrow%7D_W
LaTeX Math Inline
body--uriencoded--q%5e%7B\downarrow%7D_G

injected water surface flowrate,  gas surface flowrate

LaTeX Math Inline
bodyB_w, \, B_o, \, B_g

formation volume factors for wateroilgas

LaTeX Math Inline
bodyR_s, \, R_v

Solution GOR and Vaporized oil ratio at sandface pressure/temperature conditions


The total sandface flowrate 

LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_t
 of production is related to Liquid production rate 
LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D_L
as:

LaTeX Math Block
anchorqt
alignmentleft
q^{\uparrow}_t = \Big[ B_w Y_W + \Big( \, (B_o - R_s B_g) +  Y_G \cdot (B_gq_O
+ \frac{B_g - R_v B_o}{1 - R_v RB_s}o) \, q_G =
  \Big) \cdot (1-Y_W) \Big] \cdot q^{\uparrow}_L

where

LaTeX Math Inline
body--uriencoded--\displaystyle Y_W = \frac%7Bq%5e%7B\uparrow%7D_W%7D%7Bq%5e%7B\uparrow%7D_L%7D

Production Water Cut

LaTeX Math Inline
body--uriencoded--\displaystyle Y_G = \frac%7Bq%5e%7B\uparrow%7D_G%7D%7Bq%5e%7B\uparrow%7D_O%7D

Production Gas-Oil-Ratio = GOR



Expand
titleDerivation

Starting with definition of Total sandface flowrate 

LaTeX Math Block Reference
anchorqt_VO
pageTotal sandface flowrate = qt
 and substituting the expression of Oil surface flowrateGas surface flowrateWater surface flowrate through Liquid production rate one arrives to 
LaTeX Math Block Reference
anchorqt
.


It simplifies for the 
Black Oil model (

LaTeX Math Inline
bodyR_v = 0
) to:

LaTeX Math Block
anchor42VE8
alignmentleft
q^{\uparrow}_t = B_w \, qq^{\uparrow}_W
 + (B_o - R_s \, qB_Og) \, \frac{1 - R_{sn}}{1 - R_{vn} R_{sn}} 
+ B_g  \, q_G \, \frac{1 - R_{vn}}{1 - R_{vn} R_{sn}}

where

q^{\uparrow}_O + B_g  \, q^{\uparrow}_G

or

LaTeX Math Block
anchorBA9QP
alignmentleft
q^{\uparrow}_t = \Big[ B_w Y_W + \Big( \, (B_o - R_s B_g) + Y_G \cdot B_g \, \Big) \cdot (1-Y_W) \Big] \cdot q^{\uparrow}_L


It simplifies further down to production from
undersaturated reservoir as:

LaTeX Math Block
anchor4OV4F
alignmentleft
q^{\uparrow}_t = B_w \, q^{\uparrow}_W + B_o \, q^{\uparrow}_O = \Big[ B_w Y_W + B_o \cdot (1- Y_W) \Big] \cdot q^{\uparrow}_L

and even simpler for single-phase fluid (water, dead oil or dry gas) with  surface flow rate

LaTeX Math Inline
body--uriencoded--q%5e%7B\uparrow%7D
 and formation volume factor B as below:

LaTeX Math Block
anchorVKDEW
alignmentleft
q^{\uparrow}_t = q^{\uparrow} B, \quad {\rm meaning:} \quad q_t = q^{\uparrow}_W \cdot B_w \quad {\rm or} \quad q_t = q^{\uparrow}_O \cdot B_o \quad {\rm or} \quad q_t = q^{\uparrow}_G \cdot B_G


See Also

...

Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing (WT) / Flowrate Testing / Flowrate

Well & Reservoir Surveillance ]

Sandface flowrates ] [ Oil sandface flowrate ] [ Gas sandface flowrate ] [ Water sandface flowrate ] 

Surface flowrates ] [ Oil surface flowrate ] [ Gas surface flowrate ] [ Water surface flowrate ] [ Liquid production rate ]

Non-linear multi-phase diffusion derivation @model ]

...

LaTeX Math Inline
body\{ q_W, \, q_O, \, q_G \}

...

LaTeX Math Inline
body\{ B_W, \, B_O, \, B_G \}

...

LaTeX Math Inline
body\{ R_s, \, R_v \}

...