FIRST IS DETERMINING THE CAUSE OF DROP FLOW
It is impossible for all low-production wells apply the same standard methods of recovery/recompletion.
Accurate geological analysis allows to determine the cause of the fall inflow in the well, but this would require additional information. Location map, test results, production and exploitation history by oil, gas, water and pressure, well logging, including neighboring wells, perhaps core analysis, and sometimes require other additional data.
According to the analysis of oil wells, registered in state and national databases, for the period of operation of the well production rate drops to 10-12 bbl./day, and in many cases to zero.
MOST FREQUENTLY AND MAIN CAUSES DROP FLOW
Along with the above reasons of drop flow, there is one more very important moment. For the most cases, affect the entire future work of the well, this is initial opening of the casing, cement and productive layer.
Research has shown that almost the main reason for fall production rate are the initial methods of opening the productive formation, among which a leading position occupies the gun or cumulative perforation in the old wells.
too small depth of penetration
too small opening zone
too small drainage surface area
bad hydrodynamic connection the well with producing formation
malicious impact force on the casing, cement sheath and productive formation mechanical damage of casing
mechanical damage or destruction of cement sheath (with the formation of cracks and subsequent increase under the influence of circular tangential compressive stress conditions and rock pressure, which contributes to the water overflows from the watering layers, and subsequent flooding of the productive formation)
formation of melted borders, clogging the productive formation