TABLE OF CONTENTS Methods for subsurface fluid control involve modifying production or injection profiles of wells to:
Divert injected fluid from thief zones into previously underswept zones to improve flood conformance
Shut off undesirable produced fluids
Control water or gas coning
Repair casing leaks
Repair cement failures
There are two benefits from using profile modification technology in field operations:
Increased profitability from increased oil recovery, and
Reduced volume and cost of water lifting and disposal in production or waterflood operations
Proper well and process selection, job design, job performance, and placement are important factors for successful results. These items are discussed in more detail in the following sections.
The purpose of this section is to provide information on available processes for injection and production profile control and their applications. Various mechanical, cement, and chemical methods for controlling water injection and production are discussed.
Modification of the production or injection flow profile of a well is desirable in cases of excess water or gas production, as well as in underinvaded zones of secondary or tertiary projects. Figure 10-6 illustrates the types of profile control problems commonly encountered that result in high water production rates or poor waterflood sweep efficiency. These are:
Casing leak. Corrosion holes, collar failures, split casing, which leaks water from an aquifer into the well. This is most often an old-casing problem.
Mechanical failures. A packer leaks water from above or below into the producing zone. Casing shoe leaks.
