MXPA97008596A - Method and equipment for recording and processing digital images of perforac nuclears - Google Patents

Abstract

A method for recording and processing digital images of a flattened perforation core (10), characterized in that the images of the core drilling (10) are recorded directly by means of a high resolution digital camera (9) that moves in equal intervals along the core of drilling (10). While the recordings are taken, the drill core is illuminated by a constant light in a direction that has an angle (a) with respect to the core of the drill core, as the recorded digital data is transferred to a computer (6) for processing and subsequent storage

Description

METHOD AND EQUIPMENT FOR RECORDING AND PROCESSING DIGITAL IMAGES OF DRILLING NUCLEI The present invention relates to a method and equipment for recording and processing digital images of drill cores, taken from underground geological formations. The recording and processing shall be understood here as digital photography and recording, together with the handling, display and statistical analysis of such images by means of appropriate data equipment and software.

When oil and gas drilling operations are carried out, frequently taken samples are taken, such as drilling cores from formations that may contain oil and / or gas. The drilling cores are subject to different investigations, to determine the petro-physical properties of the formations from which the cores are collected, they will be referred to as petro-physical properties related to porosity, permeability, grain size and size distribution. grain, sand and clay relationships, together with the quantification of the main minerals in the stone sand.

REF: 26124 Previously it has been known to take ordinary color photographs on scales of 1: 5, 1: 4 and sometimes 1: 2, of perforated nuclei under the influence of visible and ultraviolet light.

To facilitate the handling of such photographs, which are normally taken in a larger number of samples, they have been scanned by means of a manual scanner ("scanner") and stored in electronic data recorders (digitized).

Meanwhile, there are currently no methods or techniques available that make use of the stored images or data to calculate (predict) the properties of the drill cores. The disadvantage in relation to such manual and photographic scans is that the digitized images created by a manual scanner are not of an unlimited length, and are usually present in a fixed format (scale). Moreover, the quality of the film and the development process vary, since a plurality of service companies are commonly involved in the management of drilling cores. Different companies have different types of cameras, film qualities and lighting conditions. In addition, the quality of the image deteriorates with the passage of time. Reprinting (making new reports) leads to reduced image quality. In addition, the digitalization of the images in this manual way, also depends on: Equipment (browser type / resolution) Image quality (positive or negative) The format of the movie (1: 5, 1: 4, 1: 2) The quality of a manually scanned digital image is therefore unsatisfactory for the analysis of images and the prediction of petro-physical parameters. In addition, manual scanning represents an additional intermediate and labor consuming stage.

In accordance with the present invention, a method and equipment is provided that makes it possible to predict the petro-physical parameters of the drill cores, sampled while drilling oil or gas, based on digital image analysis.

The method according to the present invention, is characterized in that the images are recorded directly by means of a high-resolution digital camera, which moves along the core of perforation in equal intervals, as the drill core while carrying After the recordings, it is illuminated by a constant light at an angle (a) with respect to the surface of the drill core, while the recorded digital data is transferred to the computer for further processing and storage.

Furthermore, the equipment is characterized in that it comprises a frame with a table for holding the flattened drill core, to which a moving digital camera is placed on top of the table in conjunction with an upper part of the frame, and where the camera is adapted for movements along the drilling core, light sources for the constant irradiation of light at an angle (a) with respect to the drill core, together with a computer for recording, processing and storing the digital data.

The dependent claims 2 to 4 and 6 to 9 define the advantageous features of the invention.

On the other hand, until now it has been referred to as impossible to make use of the implicit information in accordance with the invention, due to its enormous complexity, if a quantification method is based on a deductive model to generate light / shadow patterns outside of the "first principles" physics. The invention is based on the inverted definition of the problem. Since the light / shadow pattern is empirically characterized, it will be said that this complicated two-dimensional pattern is transformed into other forms of simpler one-dimensional vector expressions, which are easier to incorporate into statistical calibration techniques (multivariate calibration-PLS ), it will now be possible to calibrate the known petro-physical parameters from sandy stones, directly with these new implicit expressions. A central and critical factor of success for this composite method will be represented by a sequential application of operators of traditional image analytic textures with a new methodology implemented to characterize complex measurement sequences, AMT (Angle Measurement Technique for short). English) . The AMT method is described in the literature, but until now it has only been used in geomorphological works that totally differ from this new field of application, Formation Evaluation Work Stations (FEW). The possibility of a direct correlation of video images and therefore of a Predictor installation of Petro-Physical Parameters based on Video (VPPP for its acronym in English) of the FEW concept, is directly related to this new innovative combination of Special illumination of the surface of the sandy stone, derivation of the texture of the resulting light / shadow pattern, linearization of the texture image resulting from the AMT analysis, accompanied by a final multivariate calibration empirical PLS vis-a-vis laboratory measurements for the desired types of sandy stone parameters.

Next, the invention will be described further by making examples with reference to the drawings wherein: Fig. 1 shows a recording polling machine according to the invention for digital images of cores in a frontal view, Fig. 2 shows the same in a side view.

The recording polling machine according to the invention consists, as shown in FIGS. 1 and 2, of a frame 1 with a table 2, for holding a flattened core 10, a moving position system 3, 4 including the camera 9 and the lighting 7, 8, together with an automatic control and operation system comprising a computer 6 and a control-interruption cabinet 5.

The frame 1 can advantageously be manufactured from aluminum profiles, but its dimensions must be sufficient to ensure a stable and vibration-free function. The table 2 is fixed to the frame 1 and is, as previously mentioned, adapted to hold a flattened drill core 10 at a distance that is constant with respect to the camera 9. It must be dimensioned lengthwise to handle the cores of drilling to a minimum of 3 meters.

The camera 9 is a high-resolution digital video camera of the so-called "frame capture" type and is placed on a carriage 11 which is movably supported along a rail (not shown) by means of a rail system (also not shown) in a part of the upper frame 3. The screw is driven by a step motor 4 which advantageously can have 200 stages in one revolution. If the screw is supplied with a screw space of 5 millimeters for one revolution, this will give a movement ("linear resolution") of 0.025 millimeters per step.

The car is, in addition to the camera, supplied with two lamps of day 8 and two armours for ultraviolet light 7, adapted to illuminate the core sample while recording the images. The lighting sources are therefore moved together with the camera while the images are being recorded. In this way, the lighting conditions are kept constant along the core of the perforation. It should be noted that each of the light sources 8 and the light sources 7, are positioned and controlled in such a way that the drill core can be illuminated symmetrically or non-symmetrically at different angles of incidence of the input light. When recording images that are only for the purpose of showing the perforation cores, symmetric lighting at an angle of 20-60 ° will be used. The images registered for use in statistical analysis, are taken by using asymmetric lighting, where the angle of incidence is 5-30 °, to achieve the best possible light / shadow pattern while recording the images.

All functions are controlled by means of a computer (PC) 6 that is supplied with a program to position the camera, calibration, recording functions, data storage and overlapping images, etc. All electrical components, such as the relays, fuses and electrical connections, between the PC and the hardware part of the equipment (motor and lighting), are placed in the interruption cabinet 5.

The operation of the equipment is as follows: the carriage 11 together with the camera 9 and the lighting 7, 8, moves along the rail in part 3 of the frame fixed above in a sequence by stages, as the camera registers an image of a stage of the drill core 11 fastened in the table 2 below.

The camera, which can have a resolution of up to 4400 x 3400 points, digitally records the images and transfers them electronically through cable 12 to the PC 6. A self-developed software for the PC, which will not be described further here, manages and synchronizes the motor control along with the operation of the camera and the light. Based on the data that is recorded in this way with respect to the position of the camera and the lighting conditions, the images of the drill core are placed together (overlapped) electronically to a larger image than, per se, together with the The records of the plural core samples represent the geological structure of a complete well. The composite images are stored on the PC and can be distributed / given to the users / clients on a hard disk, magnetic tape or optical discs.

In addition to the software for recording, processing and storing digital images as mentioned above, software has been developed to visualize the images of the drilling cores on a data monitor, together with the software for the statistical analysis of digitized images.

The software for image monitoring is a self-developed program used to display digital images of the 24-bit core on a data monitor. The monitor can handle images of TIFF and BMP format. The images can be electronically overlapped and can be monitored as a continuous image (for example a complete well), unlimited. By displaying images in this way, they are based on a novel technique called segmented file reading, which is a method for rapid visualization of digital images that extend beyond the available place in the data monitor. The image segments are read from the file to the buffer memory, by means of a backup processing.

This type of load is controlled based on the last movements of the user in the image. The method implies that in approximately 90% of the cases, there will be a sufficient number of image segments in the memory, to cover the part of the image that the user wishes to see. This results in a substantially faster visualization of the images, compared to ordinary methods based on reading data directly from the file. The program can also show records of file data, correlated in depth and scaled correctly, next to the scanned image. The records will be scaled automatically to the image as the image changes. The program can operate in 4 modes: 1 image + 3 registers 2 images + 2 registers 3 images Approach an image in 4: 1 and 8: 1 scale In relation to the software for statistical analysis, due to the application of small angle, asymmetric lighting of the drilling cores, it is now possible to obtain a light / shadow pattern in the images that by means of the software can be used to calculate / predict : Average grain size and grain size distribution Porosity Permeability Primary mineralogy The quantification of the properties will depend on the reflection of the visible light and / or the origin of a light / shadow pattern in a form of diagnosis and quantification.

Having described the invention as above, property is claimed as contained in the following

Claims (9)

1. A method for recording and processing digital images of flattened drill cores, characterized in that the images are recorded directly outside the drill core, by means of a high resolution digital camera that moves at equal intervals along the core of piercing, wherein the piercing core is illuminated by constant light at an angle (a) with respect to the surface of the piercing core, when the recordings are taken, and where the recorded digital data is transferred to a computer for processing and subsequent storage.

2. The method according to claim 1, characterized in that the drill core is illuminated by the use of white and ultraviolet light.

3. The method according to claims 1 and 2, characterized in that the drill core is illuminated by an asymmetric illumination at an angle of incidence (a) between 20-60 °

4. The method according to claims 1 and 2, characterized in that the drill core is illuminated by an asymmetric illumination at an angle of incidence (a) between 5-10 °.

5. A device for recording and processing digital images of flattened drill cores, characterized in that it comprises a frame with a table for holding the flattened drill core, whereby a mobile digital camera is placed on top of the table, in conjunction with a part upper of the frame, the camera is adapted for movements along the drill core, the light sources for the constant irradiation of light at an angle (a) with respect to the drill core, together with a computer for the automatic positioning of the camera, digitalization, processing and storage of digital data.

6. The equipment according to claim 5, characterized in that the light sources comprise radiant sources of white light (day light with a Kelvin degree number> 3200) and ultraviolet light.

7. The equipment according to claims 5 and 6, characterized in that the light source radiates light in a direction (a) for the symmetrical and asymmetric illumination respectively.

8. The equipment according to claims 5 and 7, characterized in that the camera and the light source are placed on a common carriage which is adapted for movements along the rails placed on the upper part of the frame.

9. The equipment according to claim 8, characterized in that the carriage is moved by means of a screw driven by a step motor, the step motor being controlled by a computer.