NON CONVENTIONAL RESERVOIRS

[flipper]

HI ALL ,
PLEASE CAN ANYONE TELL ME THE DIFFERENCE BETWEEN TIGHT GAS/ COALBED METHANE (CBM)/ SHALE GAS/SHALEOIL??
THANK YOU IN ADVANCE

[FANARCO]

Tight Gas is that gas reservoir where the formation porosity less than 10 %.

CBM is to extract Methane gas from the coal. it needs some process which is not listed here.

Shale gas/shale oil reservoirs is low permeability which is less than .1 md and require a hydraulic fracturing

i hope these meanings to be satisfied and any of our expert members can add more.

[flipper]

OK THANK YOU FANARCO BUT WHY TIGHT GAS IS CLASSIFIED AS NON CONVENTIONAL RESSOURCES?

[FANARCO]

Because it needs some special treatments. i.e. in conventional gas you can perforate then produce

but in tight gas you have to perforate then frac then produce


there are more steps but im not familiar with that type of reservoir.

[soman703]

CBM stands for coal bed methane where gas (typically CH4 and CO2) is sorbed under pressure into the large internal surface area of coal. The methane can have up to 6 to 7 times the volume of methane found in conventional gas reservoir.

Basics of CBM production can be given as follows
1. Relatively low gas production rate in early production time, which is called de-watering stage.
2. By the time, gas production rate increases and more stable as water is produced, pressure lowered, and gas desorbs and flows into fracture network.
3. Subsequently, gas production will reach hyperbolic/harmonic decline rates.
4. Generally it requires closer well spacing and hydraulic fracturing.

To support CBM production, mainly CBM well needs artificial lift right away to pump-off water before gas will flow at optimal rates. PCP (progressive cavity pump), ESP (electric submersible pump) and SRP (sucker rod pump) are production lifting options in the early stage. However for better solid handling (e.g. coal, shale, sand), some operating companies prefer to use PCP rather than the others.

As water production drops in time and gas production increases, the operating company may change the production lifting to plunger lift to support high gas liquid ratio production.

[FANARCO]

CBM stands for coal bed methane where gas (typically CH4 and CO2) is sorbed under pressure into the large internal surface area of coal. The methane can have up to 6 to 7 times the volume of methane found in conventional gas reservoir.

Basics of CBM production can be given as follows
1. Relatively low gas production rate in early production time, which is called de-watering stage.
2. By the time, gas production rate increases and more stable as water is produced, pressure lowered, and gas desorbs and flows into fracture network.
3. Subsequently, gas production will reach hyperbolic/harmonic decline rates.
4. Generally it requires closer well spacing and hydraulic fracturing.

To support CBM production, mainly CBM well needs artificial lift right away to pump-off water before gas will flow at optimal rates. PCP (progressive cavity pump), ESP (electric submersible pump) and SRP (sucker rod pump) are production lifting options in the early stage. However for better solid handling (e.g. coal, shale, sand), some operating companies prefer to use PCP rather than the others.

As water production drops in time and gas production increases, the operating company may change the production lifting to plunger lift to support high gas liquid ratio production.

Great input.

better to make a new thread for CBM...

[soman703]

Thankyou dear Fanarco.

Its done. Please feel free to add more knowledge that you all might know from experiences!

[Javadova]

i could not find this material. is it possble to get it? arzujavadova@yahoo.com

[FANARCO]

i could not find this material. is it possble to get it? arzujavadova@yahoo.com

What material...