Skin bypass frace: Proof that size is not important

摘要

Hydraulic Frachuring is probably the most widely used stimulation technique in the world today. Practitioners often have pre-conceptions that the process involves huge quantities of equipment and materials, often at vast cost. It is true that this is sometimes necessary. However, often all that is needed to produce effective stimulation-a meaningful increase in production that more than offsets the cost of the treatment and meets realistic production targets -is a conductive path through the region of near wellbore damage. This paper sets out to describe the processes involved in producing these skinbypass fracs, and with the aid of computer simulations, to demonstrate the effectiveness of theses treatments. The methods detailed in this paper are designed to produced fractures with a maximum propped length of +/-40 ft. Often these fractures will not completely cover the zone vertically. In spite of this, the data from the simulation studies clearly shows the effectiveness of these treatments. The results also show how variables such as skin factor, permeability, drawdown, net height, frac height, frac length, frac positioning, fracture conductivity, reservoir fluid properties and wellbore geometry influence the production increase. The conclusions drawn from these results are that in many wells. Effective stimulation can be produced by small, cheap hydraulic fractures, which employ the minimum of equipment and materials. Skin-bypass fractures are cheap, use minimal equipment and are easy to operate. Furthermore, they are environmentally friendly. They are of benefit all over the world where limitations such as cost, deck space, deck loading and crane size often prevent "conventional" hydraulic fracturing. Skinbypass fracturing is a viable alternative to matrix acidizing, particularly in formations where unfavourable mineralogy limits the use of conventional acid systems.