Well Operations Reference guide

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Well Operations

Introduction

The Well Operations Module is currently primarily focused on the Drilling of a Well from the operations point of view. Other operations such as completions will be added in the future. The starting point was based upon the CAODC (Canadian Association of Oil Well Drilling Contractors) Electronic Tour Sheet File Standard Specification Version 2.2 from October 2003. As this was an older standard that was being reviewed, it was used as the starting point, but as the work progressed, various sections needed expansion due to new data groups and elements being identified and more detailed requirements from the business side and also from the regulatory side. The scope to be covered started with the spudding of the well through all of the drilling up to and including the setting of production casing. The current scope does not continue into the completion phase for the well.

Business Process Overview

Drilling a Well

To drill a well it is necessary to have a drilling rig. This rig must be setup (or positioned) at the proper surface location. The modeling process covers both onshore wells and offshore wells.

The first step is for the construction crew to build a road and a drill site to accommodate the drilling rig. The rig is then moved in and setup. The basic concept is that a drill bit is put on the end of a drill string and turned into the ground. As the bit gets deeper, additional drill pipe is added to the string.

Drilling mud is used to lubricate the drill bit and also to bring the cuttings from the drilling process to the surface for removal. Drilling mud can be made up of many additives that can affect it’s weight and density. In addition to the rig, there are other pieces of equipment such as the mud pumps and shakers that have related data.

In the early days wells were normally drilled vertically. As the technology progressed, the capability to do some deviation of the bit was used resulting in deviated or directional wells. Most recently the technology has improved to allow for the drilling of horizontal wells that can follow a formation.

As the well is drilled, surface casing must be inserted and cemented, followed by intermediate casing and finally production casing if the well will produce.

Drilling is a process that very rarely stops once the well is spud. The drilling is done in tour’s or periods. There are usually either 2 – 12 hour tours or 3 – 8 hour tours depending upon the drilling crews that are available. All of the information is tracked according to these periods, while some of may be accumulated to intervals. Periods are based on days and time and intervals are based upon depth. So a drill bit could be used for multiple days and periods but would also be associated with one interval based upon the run in depth and run out depth. Both periods and intervals are related to the “WELL”. Information is captured for the period and accumulated to the interval.

Data Capture

For each period – record the starting time, depth, weather and crew information. Do the start of period checks Do inventory on rig and on site Record the necessary values Mud weight, density, additives Drilling – string weight, rpm Do the drilling – much of this information is captured electronically and can be uploaded to the data base. Any changes to mud need to be identified and interval(s) finalized Deliveries causing changes in inventories must be recorded If an incident occurs, the information is captured to the HS&E module and related to the well and period(s). May need to change drill bit – need to record condition etc plus end of interval for bit.

Data Groupings and Relations within the model

WELL LOCATIONS - DIRECTIONAL SURVEY

Directional surveys are taken while drilling deviated or horizontal well and are normally processed after the final drilling operation. This data is then stored in the WELL LOCATIONS group under the directional survey set of tables The Well Directional Survey table contains header information about directional surveys which have been performed on a wellbore. This downhole survey charts the degree of departure of the wellbore from vertical and the direction of departure. Since many directional surveys can be conducted on a wellbore, the survey number is included as part of the primary key to uniquely identify the survey.. The Well Directional Survey table records the individual directional survey points along the wellbore during a downhole survey. The measurements at the survey points record the inclination from the vertical axis that the wellbore trends and the clockwise departure of the survey point from the north reference used in the directional survey.

EQUIPMENT

Use this table to describe pieces of equipment that are real, as opposed to represented in a catalogue. May be any kind of equipment, such as trucks, rigs, computers, microscopes, gauges etc.

SAMPLE ANALYSIS

Use this table to keep track of the details about an analysis project, just as who did the analysis, when it was done and so on.

SUPPORT FACILITIES

A support facility provides operational support for activities. These facilities may include roads, transmission towers, airstrips, vessels, docks and so on. Sub types are used to fully describe each type of support facility. All relationships with other modules are managed through the parent table.

BUSINESS ASSOCIATES

Business Associates are involved in every business process and transaction. Detailed descriptive meta data about who you are doing business with adds value to the information you keep. Properly managing business associate information also can help you ensure that your legal obligations are properly tracked and managed. Detailed information about business associates can be tracked in the business associates module including: • Names, including naming history, acquisitions and mergers • Current and historical addresses and contact information • Employee (consultant etc) / employer relationships • Organizational structures • Levels of authority, including spending limits and authority over specific business objects • Services provided for wells, seismic, obligations, land rights, contracts and more • Permits and licenses to conduct operations, from drivers licenses to permits to handle explosives • User preferences such as meeting times and locations or technical preferences for well log access.

HEALTH, SAFETY AND ENVIRONMENT

The initial starting point included very limited information about “Incidents”. Due to relevance, this section was expanded to track more detail and an initial module for Health, Safety and Environment was designed. This module is focused on incidents and their details and can be related back to well and / or drill period using the HSE_INCIDENT_COMPONENT table.

CATALOGUES and SETS

Because there are many suppliers of equipment, additives and services to the drilling process, the concept of catalogues and sets has been implemented. The catalogue model is designed to store the catalogues of the various suppliers with their associated naming conventions and specifications and allow for aliasing of the names. The concept of a set – that of a set id and an associated group of detailed items is also used. As example, most drilling companies have a set of checks that are done each time a crew starts a new period. Each drilling company would have its own set of checks that would probably be the same. This set concept is also useful for regulatory reporting as each agency normally has its own set of codes to describe the drilling information to be submitted.

Definitions

While the following terms may be described in a number of different ways, these definitions attempt to describe each term in the context of the PPDM model.

Period

Internationally, there may be 1, 2 or 3 drilling periods each 24 hours. In some jurisdictions, reporting may occur for more than one period, such as for an 8 hour tour shift and a 24 daily summary

Interval

An interval is depth related with a top or starting or run-in depth or run-in and a base or ending or run-out depth. The interval is used for tracking information that typically spans periods. As an example when a drill bit is changed during the middle of a period, the interval for the first drill bit would be “closed off” with the base depth being the depth the drill bit drilled to; and a new interval record would be created for the new drill bit with the starting depth as the drill that the drill bit started to drill. For drilling mud intervals (required to track the changing composition of the mud) the interval could be across multiple drilling periods or there could be multiple mud intervals within the period.

Incident

“Incident” means an occurrence or event, either human-caused or natural phenomena, that requires action by emergency personnel to prevent or minimize loss of life or damage to property or the environment. The type of incident varies according to petroleum industry activities and could include releases of toxic gas such as hydrogen sulphide, fluid releases such as oil or salt water, or well-site blowouts.. “Incident Classification” means a system which examines the risk level to members of the public following an incident and assigns a level of emergency based on the consequence of the incident and the likelihood of the incident escalating

Set

The concept of a set – is that of a set identifier and an associated group of detailed items. As example, most drilling companies have a set of checks that are done each time a crew starts a new period. Each drilling company would have its own set of checks that would probably be similar but not identical. This set concept is also useful for regulatory reporting as each agency normally has its own set of codes to describe the drilling information to be submitted.

Catalogue

Because there are many suppliers of equipment, additives and services to the drilling process, the concept of catalogues has been implemented. The catalogue model is designed to store the catalogues of the various suppliers with their associated naming conventions and specifications and allow for aliasing of the names.

Model Overview

Integration

Integration is the key to managing the PPDM Data Model properly. Information critical to managing data throughout its life cycle is managed in many support and business modules in PPDM version 3.8:

Support Modules

PPDM Unit Measure: captures the default stored unit of measure for any measured value in the database and conversion factors.