Method for vertical fracture growth control

In a cased borehole extending down through a hydrocarbon producing formation which has an upper low water strata and a lower high water strata which meet along an oil/water interface adjacent the casing perforations, the method of treating the formation comprising the steps of:

• (1) pumping a carrier fluid laden with relatively fine grains of material down a tubing string and into the lower perforations, while at the same time;
• (2) pumping a fracturing fluid laden with relatively coarse grains of material down the casing annulus and into the upper perforations;
• (3) continuing to simultaneously carry out steps (1) and (2) so that the carrier laden with relatively fine material forms a barrier between the upper low water strata and the lower high water strata;
• and,
• (4) the fracturing fluid laden with relatively coarse material is forced to flow into and fracture the low water strata, while the relatively coarse material enters the fractured zone and props open the formation.

In a borehole which extends downhole through a production zone;

• wherein the production zone includes a low water strata which produces hydrocarbons, and a high water strata which produces water, the method of isolating one strata from the other and treating one of the stratas with a treatment chemical comprising the steps of:
• (1) simultaneously pumping a first treatment chemical and a second treatment chemical along separate flow paths downhole into the borehole;
• (2) conducting said first treatment chemical into the low water strata;
• (3) conducting said second treatment chemical into the high water strata;
• (4) said second treatment chemical is a carrier fluid having barrier forming material therein which drops out to form a barrier between the high and low water strata so that the first treatment chemical is directed into the low water strata.