Research On Corrected Depth Computation Of Perforating Depth And Realization Of Accessorial System

The application of perforating technique to well completion is widely used in exploitation of oilfields in the world. Perforating Depth Computing is fairly important, which decides the precision and accuracy of perforation. While, correction depth that has an important significance to guarantee the quality of perforation is a necessary aspect of Perforating Depth Computing.Perforating depth comes from two loggings, one is logging comprehensive explanation achievement drawing which decides perforating depth requisition roots, and the other one is pre-magnetic drawing which determines casing collar depth. The errors of the two logging depths would be subjected to some comprehensive factors, such as logging cable's extending or shrinking, machine, people, and environment and so on. To eliminate these depth errors and get depth unified, we adopt natural gamma curve in pre-magnetic drawing as intermediary to unify depth to logging explanation achievement drawing, which is perforating, corrected depth.At present, most of oilfields in our country, the whole processes of the perforating depth correcting are still realized by artificial work, not getting rid of hand working model. And the low degree of modernization and laggard correcting methods certainly would increase the rate of produce of correcting errors and make construction precision low, so that thin reservoir maybe cannot be exploited, which will seriously affect the production and development of oilfields.On this background, in this paper the research on perforating depth correcting is studied. Main contents are as follows:First, in order to improve the precision of perforating depth correcting, we make the conditions of post-casting curve approximate to that of pre-casting curve, applying B-spline to transform the post-casting well-logging signal and extracting the signal characteristics of logging curve in post-casing drawing. Some preparation of data for future work should be made, like building up matching databases and completing the transformation of data format of perforating depth correction.Second, in accordance with the patterns of logging trace, Mathematics Methods is used to extract the curve Features; the interrelationship between the intensity Natural gamma-ray and clay content determines the range of sandstone and mudstone and divide the boundary of layers; the range of natural gamma, sandstone and mudstone help to extract Characteristics layer of natural gamma curves; by use of layer-related contrast, put forward a mathematical model to get correction value and to prove the result within the error range and improve the calculation accuracy. Third, this research has completed the auxiliary corrected depth system of perforation depth computation. It has realized the playback of standard curve and regional curve, the display of the depth of the symbol, and it can auxiliary natural gamma to correct depth, and it achieves some auxiliary functions about operation, and so on. Finally, the research contrasts correct value from system and traditional way compared with that of the traditional way, the method of obtaining correction value of system can prove that the auxiliary corrected depth system reduces the time and increases the precision.