WO1998053173A2

WO1998053173A2 - Improvements relating to strata logging on computer

Info

Publication number: WO1998053173A2
Application number: PCT/NZ1998/000061
Authority: WO
Inventors: Cecil Barton Woodford
Original assignee: Cecil Barton Woodford
Priority date: 1997-05-21
Filing date: 1998-05-21
Publication date: 1998-11-26
Also published as: AU7557298A; WO1998053173A3

Abstract

A logging system in which information relating to physical attributes of underground strata is recorded using pictorial representations. A library of representations (35) to which further representations may be added in the field is included in the system. The representations (52) generally contain coloured elements which indicate at least some physical attributes of the strata. Preferably each representation (52) is recorded as a database entry having an attribute description in words (51) and a code (50).

Description

IMPROVEMENTS RELATING TO STRATA LOGGING ON COMPUTER

FIELD OF THE INVENTION

This invention relates to methods of recording and presenting information obtained while drilling boreholes, in particular but not solely boreholes for water wells.

BACKGROUND TO THE INVENTION

Various computer based systems are available for use in recording and presenting logging data which is obtained when drilling boreholes. Examples are found in NZ 210946 entitled "Quantitative Determination by Elemental Logging of Subsurface Formation Properties" and US 5,237,539 entitled "System and Method for Processing and Displaying Well Logging Data during Drilling". None of these existing systems use a pictorial or similarly visual presentation of information relating to the strata through which a borehole passes.

Boreholes are drilled for various purposes including water wells. The procedures are generally similar and may involve investigation drilling, coring, sampling and penetration testing. A consulting engineer for example, would require strata information while preparing plans for the foundations of a large building or road construction, or before setting up a heavy storage area or placing piles for a wharf. It is important that physical attributes of the formations down each borehole are recorded in a simple and accurate manner to avoid unnecessary expense in redrilling.

There has always been a need for geologists, hydrologists, engineers, water resource officers, drill workers and others to be able to recognise physical attributes of the strata in underground formations encountered during a drilling operation. Bulk composition and age of the strata are particularly important, and these may include earth and rock formations, clay sediment, and carbonaceous deposits within gravel or clay for example.

Dozens and perhaps hundreds of different strata may be encountered when wells are drilled over a wide geographical area and the information from each site must be recorded in a reliable and useful fashion.

SUBSTITUE SHEET (Rule 26) SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide improved systems for recordal and presentation of well logging data, or at least to provide the public with a useful choice.

Accordingly, in one aspect, the invention may broadly be said to consist in a logging system in which information relating to physical attributes of underground strata is recorded using pictorial representations. Preferably the system includes a library of representations to which further representations may be added in the field. Preferably the representations include coloured elements which indicate at least some physical attributes.

Preferably each representation is recorded as a database entry having an attribute description in words and a code.

In a second aspect the invention may also be said to consist in a method of recording an underground formation traversed by a borehole, comprising: determining physical attributes for a series of strata in the formation by sampling earth material at a plurality of depths in the borehole, comparing physical attributes of each sample of earth material with entries in a database of pictorial strata representations, creating a new pictorial strata representation for a sample of material which is not already stored in the database, storing any such new pictorial strata representation in the database, creating a record of the series of strata according to entries which are available in the database, and producing the record of the series of strata in pictorial form as a visual summary of the formation.

BRIEF DESCRIPTION OF DRAWINGS

A preferred embodiment of the invention will be described with respect to the accompanying drawings, of which:

Figure 1 is a schematic view of a borehole which traverses a sequence of strata,

Figure 2 is a simplified pictorial summary of the strata in Figure 1 according to the invention,

Figure 3 is modular view of a preferred software system which may be used to produce a summary as shown in Figure 2,

Figure 4 is a flowchart indicating the function of a system such as shown in Figure 3, Figures 5a to 5d show example representations of strata,

Figures 6a to 6c are example entry screens for some of the representations,

SUBSTITUE SHEET (Rule 26) Figure 7 is a more complex pictorial summary of borehole information according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to these figures it will be appreciated that the invention is in a form which may be implemented with numerous variations. It will also be appreciated that software according to the invention can be run on a variety of computer hardware systems and used in a variety of drilling projects. Details of the hardware systems and drilling rigs which might be used will be known to a skilled reader and need not be described.

Figure 1 is a simplified vertical cross section through a borehole 100 such as might be drilled for a water well or for an investigative purpose as mentioned above. The borehole traverses many layers including strata 1 to 11 of an underlying formation before reaching a water bearing stratum 12 at a depth of perhaps 100m. The strata are of various types depending on the geological history of the site, and in this example include topsoil 1, gravel 2, boulders 3, clay 4, a generally impermeable material 1 1 , and a layer of water permeable material 12 which forms an aquifer. Samples of strata encountered while drilling the borehole may be obtained in various ways such as diamond coring or push tubing techniques. Other physical or chemical tests may also be carried out and logged on the site.

Figure 2 shows a simplified pictorial summary 20 of logging information recorded on computer and presented according to the invention. The strata identified in Figure 1 are indicated in a pictorial fashion which approximately represents their visual appearance and physical makeup as found by sampling. It will be seen for example, that the representations of gravel and boulders in layers 2 and 4 are suggestive of those materials. Colours may also be used to indicate actual colour of the layer material, which in turn may indicate composition or age, or other physical properties such as water content. The record of each stratum would also normally include other numerical or textual data such as depth, thickness, penetration hardness and a description, as will be demonstrated below. A pictorial representation of this kind could be varied in many ways, and could be presented horizontally for example, or with a thickness on paper shown in proportion to actual thickness.

SUBSTITUE SHEET (Rule 26) The visual appearance of samples from a borehole can be compared with and transferred to a computer database according to the invention, in various ways. They may be retained in a labelled bag for examination and entry in the computer system by a geologist at a later date. They may be photographed or sketched for entry at a later date. Most conveniently they may be entered directly and accurately onto the computer system on site. In each case a software graphics application may be used to capture the appearance of the particular strata as a bitmap image. Once recorded in a pictorial or otherwise appropriately coded form a summary of results at a particular site are readily presented on a colour video screen or printed when required. The nature of the formations underlying the site can then be understood and compared with other sites without difficulty.

Figure 3 is a schematic diagram showing components of a computer system which may be used to record and produce pictorial logging information such as shown simplified in Figure 2 and in more detail below in Figure 7. In this case the system is configured for a water well operation. Many of the components relate to incidental functions of the system or are self explanatory, and need not be described in detail. The system operates by way of a main routine 30 with access to input and output routines 25-29 and 31-34 respectively, a library of existing strata entries 35, a routine 36 for addition of new entries, a file 37 for storing information received from a current operation, and a routine 38 for scanning the library and comparing/selecting entries for the latest sample.

In general terms, a user compares the latest sample taken from a borehole with available entries in the strata library 35 through routine 38, or perhaps considers a group of preserved samples at a later date. If an appropriate entry is found, or is created and added to the library using routine 36, a coded record is then stored in file 37. Other information relating to a particular sample, such as depth, thickness or penetration results, may be included in the file using other routines as indicated. The system provides several printout capabilities including a complete list of representations in the library, and colour printout of pump equipment installed in a well through routines 34 and 33 respectively.

Figure 4 is a flowchart outlining in general terms how the computer system of Figure 3 operates to produce a pictorial summary of strata information, and provide other functions as mentioned above. Once again elements of the system relate to incidental functions or are self explanatory and need not be described in detail. The system is set up to record a sequence of boreholes which might be drilled for a particular "owner" or customer, such

SUBSTITUE SHEET (Rule 26) as a farmer who requires a number of water wells. Other functions of the system may correlate drilling data laterally over a wide area to establish geographical patterns which for assistance in drilling other boreholes for the same or neighbouring owners. A user provides items of data relating to the current well in step 40 and selects strata representations in step 41. If an appropriate representation is not available on comparison of the current sample with existing library entries in step 42, then a new entry may be created in step 43 as described in relation to Figures 6a-6b. A full log of samples may be printed in step 44 to produce a report such as shown in Figure 7.

Another function of the system is to create a log with particular emphasis on penetration data. A user provides items of data relating to the well in step 45 and selects appropriate strata representations in step 46. New strata representations may be entered in the library in step 43 if required. A summary containing penetration and strata details may be printed as a report in step 47. An optional function involves a cross sectional printout of the borehole itself indicating equipment such as a pump which may have been installed.

Figures 5a, 5b, 5c and 5d are a selection of entries from a strata library database which has been prepared during testing of the invention. These entries have been inspired by strata which have been physically sampled during drilling procedures and added as required to prepare a summary of the current site. The library contains a series of entries for separate strata, each having a code in column 50, description in column 51 and pictorial representation in column 52. The codes are generally an abbreviated version of the description, as will be evident, so that the first entry "ang gwke ptls-g cl bd" corresponds to "angular greywacke particles, grey clay bound" for example. Each pictorial representation in turn also corresponds to the description although in most cases the correspondence is considerably clearer when colours can be taken into account. In some cases an indication of colour has been given alongside column 52 to assist where a black and white representation is no longer distinct.

Figures 6a, 6b and 6c are a selection of video screen windows showing how new entries may be added to the strata library in Figures 5a-5d. Each window allows input in three places relating to the code, description and pictorial representation as mentioned above. The screen information is presented and handled using standard functions. The pictorial representations are created largely by freehand according to the users visual interpretation of the particular sample. It is the user's responsibility to check that a new representation

SUBSTITUE SHEET (Rule 26) is sufficiently different from those existing in the library. Standard representations may be provided or suggested in versions of the system which become commercially available.

Figure 7 shows a report of an actual drilling operation containing a pictorial summary according to the invention. Various pieces of information are presented in the report including site location and detail on the water well equipment which was installed in this case. A sequence of 12 strata were sampled during the operation beginning with topsoil and gravel to a depth of 20cm, and finishing with a layer cobble and clay having a thickness of 40cm at a depth of 10.2m. Although the coloured aspect of the report is lost in reproduction, an understanding of the formations can be readily grasped from the pictorial summary.

SUBSTITUE SHEET (Rule 26)

Claims

CLAIMS:

1. A method of recording an underground formation traversed by a borehole, comprising: determining physical attributes for a series of strata in the formation by sampling earth material at a plurality of depths in the borehole, comparing physical attributes of each sample of earth material with entries in a database of pictorial strata representations, creating a new pictorial strata representation for a sample of material which is not already stored in the database, storing any such new pictorial strata representation in the database, creating a record of the series of strata according to entries which are available in the database, and producing the record of the series of strata in pictorial form as a visual summary of the formation.

SUBSTITUE SHEET (Rule 26)