Preparation and stimulation of water injection and disposal wells

There are 3 types of wells which can be considered for stimulation in injection systems: (1) new wells, drilled just for the purpose of injecting water; (2) old producing wells, being converted to injection wells; and (3) injection wells currently in use. The new injection wells should be treated in much the same manner as a new producing well. Mud damage should be removed and a stimulation treatment designed to provide the desired injectivity. Some type of acidizing or fracturing treatment is generally utilized. In converting old producing wells to injection wells, samples of deposits should be obtained from the open hole or perforated interval and analyzed to aid in determining what solvents should be used. Some typical stimulation treatments are listed. In utilizing old injection wells, a sample from the perforated interval or open hole is preferred. The types of scales and solutions for their removal are discussed in detail. A number of treating techniques are listed. A combination of several treating techniques may be necessary, as it is rarely possible to obtain a completely satisfactory stimulation treatment with only one.