Drill stem formation test is to use a drill pipe or tubing with the formation tester packer into the well test carried out under an advanced technology of oil. It can be carried out under the casing of wells have been tested, it can not under the sleeve of openhole testing; can be tested after the completion of drilling, but also in the middle of the test drilling. If it is found during drilling of oil and gas well drilling show stop, test for possible oil and gas layers evaluates production. The methods generally are: ① through the drill at the end of the drill pipe tester; ② using the following formula 入绳索 cable tester. They stand naked eye closure downhole isolation, escape the mud column pressure affects the fluid within the formation into the tester, sampling, pressure and so on. Drill (halfway) to test the effect of reducing the time and reservoirs contaminated underground works on a variety of follow-up reservoir, can effectively protect the reservoir is low pressure and low permeability reservoir and ease pollution effective means to improve the success rate of exploration One. Midway test often make oil and gas discovery in advance, for a time, is easy to arrange the next step work. Changsha Tianhe drilling Machinery Co., Ltd. Contact: Liu Xiao Mobile: 13667359853 18507482826 Website: www.cstianhezj.com E-mail: 1139239907@qq.com Address: Ningxiang Jinzhou District Yao Singapore Industrial Park on the 18th day