Well Completion in Oil Well Drilling

Well completion
The wellcompletion project is the last process of well drilling . The well completion project is not just the cement injection, but also process related to oil and gas well productivity improvement. In recent years from kinds of aspects, there came out many new understanding, ideas and innovation methods to protect project and increase the degree of wells perfection.
The well completion project is cohesion of drilling engineering and oil extraction. It is a relatively independent project, a comprehensive system engineering from oil layer drilling, well cementation, well completion, to oilproduction. The well completion project contains processes like unload casing pipe, well cementation, perforation, production casing pipe, drainage and production.

Some key scheme requiring attention
(1) the core analysis and sensitivity analysis
The core analysis: conventional, chip, X-ray diffraction and scanning electron microscopy (sem)
Sensitivity analysis: water sensitivity, speed sensitivity, and sensitivity of acid, alkali and salt
(2) open oil rock layer drilling
(3) the well completion way and method
According to the geological characteristics of oil field development mode, well difference, rock lithology, the well completion is basically divided into two categories: open hole completion and perforation completion. While, open hole completion have different methods, containing uncased hole, cut and sew screened pipe and wire wrapped liner pipe gravel filling. Perforation completion contains well-case perforation, tail pipe perforation, and wire wrapped liner pipe and gravel filling.
(4) selection of oil tubing and size of production casing
Selection of oil tubing and production casing should be based on pressure system analysis(sensitivity analysis of oil layer, well hole and the ground pipe line). And oil tubing sensitivity analysis is comprehensive analysis of the oil reservoir pressure, production, ing fluid quantity, the fluid viscosity, production stimulation measures and exploitation way.
The traditional method is to selecte production casing first ，then decide the size of oil tube.