Productive Time in Drilling and Comletion – Term Paper

Productive time and non-productive time

A time breakdown was also included to manage the duration spent on the various project activities. Monitoring the time dedicated to activity was crucial to avoid time wasting and ensure that the aligned task was completed within the scheduled time. The time breakdown data was obtained based on the daily drilling activities for the 25 days.  The equations for productive time and Nonproductive time were used to evaluate the time analysis data. 

•The following equation was used to get the productive time:

•The following equation was used to get the nonproductive time: 

It is important to understand that the non-productive time was the time that was not directly associated with the objectives of the drilling project. This was included in the time management approach to keep track on the non-productive time spent, for reasons like machine breakdown, waiting for equipment, power failure and line setting. It was also important as it revealed the possible reasons for low productivity, and the record can enable the management to improve the process or activities that slow productivity. In this context, the time spent on waiting for material, types of equipment and problems like hole-conditioning, loss circulation, hole-reaming, stuck pipe and fishing was considered unproductive and hence made minimal contribution or none to the progress of the project. Seven and half hours were spent on the problems as mentioned above while twenty and a half wasted on waiting for delayed delivery of equipment. Therefore, a total of 12.5 hours was spent, out of the total 571 hours. The record, therefore, confirms that a total of 549 hours was used in productive activities. Workers spent most of their time performing the central operations of the project, which is drilling. Precisely, 183 and half hours were dedicated to drilling. Mobilization consumed 82 of the project time, making up BHA spent 73, tripping spent 123, rig up and rig down spent 26.5, well logging spent 17.5, safety 32 and directional control spent 11 hours of the total project time. This evaluation reveals that a 96.49% of the project time was dedicated to productive activities while 3.50% of the project time was spent on NON-productive activities. 

Completion design for the horizontal well

Horizontal wells have become very popular nowadays since it has high productivity as well as it save a lot of money compared to vertical wells. Horizontal wells also expose more formation to production, which causes the pressure to drop to the well bore. This type drilling techniques is preferably drilled at the production phase rather than the exploratory with an inclination of 90o from vertical and is maintained for a certain distance to the formation. The curved well section is basically drilled from the bottom of a vertical well followed by a horizontal section directed to the formation. Having multiple holes in horizontal wells makes the entire procedure more expensive than that of the deviated conventional wells. Geological techniques are used to select a candidate reservoir and to ensure that the well had maximum and long-term productivity. The pressure drawdown in this type of wells is expected to be minimal to avoid water or gas coning. The drain hole is placed appropriately to prevent early breakthrough of water or gas. Hole cleaning, tubular stress, hole lubricity and torque and drag should be carefully evaluated to attain a successful drilling process. To achieve a horizontal profile at the demanded depth, the well’s patterns are associated with a common bottom hole assembly. The short, medium, and long radius techniques are common for horizontal techniques in which they have distinct benefits. A detailed explanation will be included in this study (Samuel O. Osisanya, 2016).

Long radius horizontal well

Horizontal wells greatly help exploration processes and this is because they provide easy access to the oil and gas reserves at higher ranges and angles. In this case, they are evidently more productive than the vertical well and this proves their higher usage in the society. Additionally, these types of wells help to gain access to the unconventional sources of reserves. In this type of long radius horizontal drilling, much of its application is in the shale rock and is common in the extraction of gas from the Marcellus Shale Formation. Due to the fact that the horizontal section of the well is at a depth, it must have a vertical part hence this type of a well resembles letter ‘J.’ The other advantage of the long radius horizontal rock is its ability to reach a wider area of rock and the natural gas that is entrapped within the rock. This this relation, drilling companies usually use the horizontal type of drilling to access more energy underground using fewer wells. This is because the vertical wells are effective in accessing the natural gas surrounding the end of the well. However, the horizontal wells can access the natural gas that surrounds the entire portion of the section that is drilled horizontally. The drilling of the long radius horizontal well proves to be more complicated that the conventional as it requires the driller to first determine the depth of the energy-rich layer which first requires the drilling of a conventional well and doing the analysis of the rock fragments that appear on the surface of each depth. The process of drilling involves the determination of the depth of shale, calculation of the appropriate spot above the shale where horizontal drilling starts then drilling proceeds to conclusion. 

Deviation survey

Deviation survey has various advantages to the process of drilling for exploration and exploitation for oil and gas. This proves the need of engineers to appreciate the relevance of the same in their daily activities. One of the advantages of deviation surveys is that they help in identifying areas for drilling as it exposes the length through the reservoir by drilling at an angle. Secondly, this type of survey reduces and prevents geographical dependence thereby improving the quality of survey. Third, this type of survey expands the range of data that can be collected thereby increasing information regarding the reservoirs and the quality of exploration. Finally, this type of survey is free from errors thereby increasing the credibility and authenticity of data and information. Results of deviation surveys are shown below:

  Deviation Surveys  

Date Depth Inclination Azimuth

8/6/2012 – – –

Sep-12 – – –

10/6/2012 – – –

11/6/2012 – – –

12/6/2012 – – –

13/6/12 – – –

14/6/12 – – –

15/6/12 – – –

16/6/12 – – –

17/6/12 – – –

18/6/12 – – –

19/6/12 – – –

20/6/12 3,669 76.16 307.37

– 3,699 78.01 306.89

– 3,728 79.69 306.22

– 3,659 82.01 305.74

– 3,791 84.44 305.91

– 3,822 86.85 306.48

21/6/12 4,458 89.56 294.06

– 4,524 89.44 293.76

– 4,587 89.26 292.8

– 4,649 89.57 293.17

– 4,712 89.32 293.3

– 4,774 89.44 293.61

22/6/12 5,242 89.2 296.12

– 5,336 88.27 301.54

– 5,398 87.96 300.82

– 5,462 87.47 300.31

– 5,523 87.35 301.06

– 5,586 87.1 301.07

23/6/12 6,088 87.84 299.62

– 6,182 87.09 299.35

– 6,275 86.79 298.07

– 6,370 86.97 298.38

– 6,465 87.03 297.81

– 6,559 85.98 297.61

24/6/12 6,746 85.86 298.64

– 6,872 85.86 299.88

– 6,967 85.61 300.15

– 7,062 87.03 302.09

– 7,157 86.47 300.58

– 7,251 85.49 298.92

25/6/12 7,346 85.24 298.95

– 7,440 86.66 299.69

– 7,557 86.74 298.29

– 7,582 87 298

Bit report

Bits are the tools that help in boring the cylindrical holes in the oil and gas industry. This is done through the process of rotary drilling for the discovery and extraction of hydrocarbons such as crude oil and natural gas. The hole diameter that the bit produces proves to be small and ranges from 3.5 inches to 30 inches although the depth produces ranges from 1000 feet to 30,000 feet. In this process, the bit breaks the subsurface formations apart by mechanical means through cutting elements of the bit through scraping, grinding or the use of compressive fracturing. The cuttings that are produced by the bit are then removed from the wellbore then returned to the surface through the process of direct circulation  

A technique that is more appropriate for drilling horizontal wells requires the usage of multiple wells and must be located throughout the reservoir. This method reduces resistance to near wellbore by elevating the total availability of the contact area between the producing wellbore and the reservoir. Moreover, this technique reduces the flowing distance of the fluid before it is produced hence reducing the overall resistance to flow. Although drilling a horizontal well is an expensive procedure, it offers numerous operations the vertical well can’t accomplish such as maximum production from small energy reservoirs and in low permeability formation, reduced invasion of unwanted formations fluids, recovery of reserve energy, access to irregular pools without additional energy and high penetration. They are heterogeneous and ultimately lead to a better recovery. The drilling skills and potential of these wells has enabled economic production from the available reserves. A closer look at increasing production from the low permeability reservoirs reveals that the horizontal can achieve this solution as described below. It is possible and efficient to drill deep lengths horizontally up to 2000 ft and increased resistance to fluid flow and dynamic control of the geometry. When a company selects a horizontal well candidate, the following factors must be considered in order to achieve maximum and long-term production from a horizontal reservoir, since utilizing the below-named parameters will improve the economics or extend the production life of the well. 

•Depth

•Reservoir temperature

•Production history

•Hydrocarbons originally in place 

•Hydrocarbon remaining 

•Anticipated completion 

•Production techniques 

•Economics and market