The construction of well P202-2H is difficult due to the long horizontal hole section and large string friction. A high safety coefficient for strings in construction is required. After the completion of drilling, there might be cement sheaths adhered to the casing wall on the horizontal hole section, and such cement sheaths are liable to fall off because of the friction or vibration caused by strings running into the horizontal hole section; as a result, the string might be buried or stuck. There are high risks of tools with large diameters entering the horizontal hole section; in particular, the existing cement sheaths or other impurities may cause a jamming of the drilling tool. The perforated interval is long and the perforating gun is in much vibration at the horizontal hole section, which may also cause a jamming of the drilling tool.
The Company has selected a premium shaft treatment process and has optimized the construction parameters to enable the shaft to meet the requirements for downhole completion tools and strings. We have also improved the perforating process, namely, specified different perforation densities for different reservoir formations to enhance the acidification efficiency, which furthest released the productivity of each reservoir formation.