I'm working to manage optimization study to select the optimum well technique (i.e., vertical, horizontal, single fracture, multiple fractures, ........) that could lead to producing at an economic flow rate in a tight gas reservoir (reservoir permeability less than 0.01 md) .
Hi Omar
The direct answer, without going into any details, is yes. You have to get rid of the tightness, any way. How thick are your reservoirs? Shale, Sandstone or Limestone? Depth? Economics depends on these factors, particularly thickness (consistent lithology),depth and length of the horizontal hole..
Not necessarily, for example, sometimes for condensate gas reservoirs or near critical oil or gas reservoirs we use hydraulic fracture to decrease pressure drawdown in a same flow rate, because in these types of reservoirs, we are going to prevent forming other phases around the well.
Omar,
One Thought! You might need to consider how the wells would be drilled horizontally if you want to frac them. The stresses directions are quite important in such case compared to your well trajectory.
Multi stage frac is a key to sustain production and unlock the potential of complex tight reservoirs. Maximizing reservoir contact may not be able to achieve the target productivity, this necessitate the need for placing packers and perform multi stage frac. Drilling wells along the minimum stress or perpendicular to it leads to creating fracs that either transverse or longitudinal to the bore hole.
I think you need to carry out a sensitivity analysis on this problem. By using correlations to calculate the productivity indices for the various options available. With this, you can make a conclusion on the most preferred method necessary to develop the reservoir. You may not even need to drill an horizontal well even. Consult Horizontal well technology by JOSHI and Production Engineering by ECONOMIDES ET AL
Its all a matter of net present value between a vertical well with multi-stages vs a lateral with multiple transverse fractures. Then if you are in a non normal stress regime, you need to consider whether you will even achieve transverse fractures as there is borehole inconsistencies, cement problems and other factors that affect fracture initiation and fracture complexity. This has been a problem in the deep Cooper Basin where the stress regime is strike-slip to reverse. I'd rely on Australian or other non-normal case histories before using rules of thumb or analogues from North America.
Omar
The straight answer for your kind of permeability(0.01 mD) is probably yes, regardless of the type of rock. In principle is a matter of area open to flow hence your horizontal section will have to be very long to achieve some sort of rate that makes economic sense. At this level of permeability there are very few options. I hope it helps
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