Abstract
Formation micro imager is applied in geological investigation of borehole which can provid much more properties than core sample collection. In this paper, the photogrammetic method is discussed during the lab test based on images. Photogrammetric technology is the technique of measuring objects (2D or 3D) from images. During the test process, 35 printed target points are set on the plastic clay which is adhere to the simulation borehole surface and taking photos from different locations to get the points’ information. The software of PhotoModeler is used to analyse these photos with fixing the origin point, the direction of 3D coordinate and the distance between any 2 target points. All these points (x, y, z) are obtained in this test by focus length of 18mm, 35mm and 55mm. There are differences between the 3 focus lengths for the same point's x, y and z. The results show that the parameters of RMS (Root Mean Square) marking residual and tightness have negative effection on the precision. We can identify the physical properties of a borehole surface (borehole breakout, fracture, et al.) accurately by this technology to improve exploration and production results utilizing advanced borehole. It also can reduce coring and associated drilling costs (partial core replacement).
