What is oil layer damage

From the drilling of the oil reservoir, during the entire development process, the oil reservoir is successively treated by drilling, cementing (cement injection), completion, sand prevention, acidification, fracturing, oil production water injection, tertiary oil production and other underground engineering treatment
.
These engineering operations require a variety of working fluids, which will invade the formation to varying degrees, and the physical and chemical reaction with the oil layer will reduce the permeability of the oil layer, resulting in a decrease in the production capacity of the oil and gas layer, and even the oil and gas cannot be recovered, which is the oil layer damage, also known as the formation (reservoir) injury
.

There are many causes of oil layer damage, mainly related to reducing the permeability of the oil layer, such as solid particle blockage, chemical precipitation blockage, oil layer clay expansion, oil layer non-inflatable particle dispersion transport, etc
.

The consequences of oil layer damage are very serious
.
For the exploration well, if the oil layer is seriously damaged, even if the oil layer is drilled, there is no production capacity during the oil test, that is, the commonly referred to as "empty well", so as to make the wrong judgment of "no oil", so that an oil and gas layer or an oil and gas field
may be missed.
For production wells, if the oil reservoir damage is serious, the wells that could have been high-yield become low-yield wells, and some wells even have no output at all, which greatly reduces the final recovery rate of the oilfield and directly affects the economic benefits
of the exploration and development of the oilfield.

Technologies related to reducing or avoiding serious consequences of oil layer damage are collectively referred to as oil layer protection technologies
.
Reservoir protection is of great significance in the entire exploration and development process of oilfield and has received increasing attention
.