Talk:Oil well

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"Extremely expensive"[edit]

The section on cost twice calls construction of oil wells "extremely expensive", but fails to say relative to what. This seems POV. It also claims that "Onshore wells can be considerably cheaper", but gives a wide price range of $1 million - $15 million, which (at current exchange rates) overlaps the range given for offshore wells. Finally, the "extremely expensive" designation seems meant to apply to oil wells as a whole, but the only examples given are offshore wells near Britain. -Dmh

For example, a mile of new 3-lane motorway costs about £20 Million, comparable to the cost of a new high-pressure, high-temperature North Sea well. Whether the well is expensive depends more on the worth of the oil it produces than the absolute cost. Presumably one does not drill a well with the expectation of losing money. -Dmh 20:53, 31 May 2006 (UTC)
I've heard that offshore drilling rigs in the Gulf of Mexico (US) currently cost around $300,000 per day to contract, while onshore drilling rigs in East Texas currently cost around $20,000 per day, and these rates are going up from month to month! One engineer for an operator company recently told me that their average cost for drilling and completing an onshore well is around $1.8 million (compared to $800,000 a couple of years ago). --Altailji 07:05, 10 July 2006 (UTC)

With rig rates currently running at 500,000 to 600,000US $ per day for the rig only a spred will cost approx US$ 750,000 plus per day , average length of time for a deep water well is 60 to 70 days = big money no wonder the Drilling companies are doing well NOW but have not always made money like this, Cheers someone on the inside. —Preceding unsigned comment added by (talk) 07:56, 12 September 2007 (UTC)

Some numbers for reference purpose:
Name of the Well Country of location Total Depth Total Cost Average Cost (USD/Meter)
Chuanke No. 1 China PRC 8,875 meters 38.8 (million USD) 4372.98 (USD/Meter) —Preceding unsigned comment added by (talk) 17:49, 15 June 2008 (UTC)

"Drill depth"[edit]

Discussion of the typical depths reached in the drilling process would be informative. I have not seen anything addressing this aspect of the process. Does the industry have standards for what might be called shallow, normal and deep? -DDD

The maximum drill depth seems to be accurate based on the "The Physics Factbook" (citations should be independently verified), but the deepest seem to be research projects or non-oil wells. The deepest oil well I could find reference to is Z-11 at Sakhalin-I, in the Sea of Okhotsk (Russia), with a depth of "11,282 meters" (37,016 feet). The term used to refer to this type of drilling is "Extended Reach Drilling (ERD)", and after a quick net search, I found the following list of the "Top 20 ERD wells" (again should be independently verified). This list is clearly old as it doesn't include Z-11, and it most likely contains a combined list of oil and non-oil wells. Finally, as mentioned above these deep wells are quite rare and it would be helpful to have an understanding of normal drill depths and costs. dain 18:47, 7 June 2007 (UTC)

just a note - those wells on the ERD list are not really very deep, in terms of depth below the surface -- the measurements, 11,000 meters etc., are along the drill string, which is at a significant angle to the surface. The next column, TVD, refers to true vertical depth - so those wells on that table are only reaching depths on the order of 1500-2800 m below surface. The deepest oil exploration well, in terms of depth below the surface, is something like 30,000 ft, in Oklahoma USA (don't have the reference at hand, sorry). Cheers Geologyguy 18:56, 7 June 2007 (UTC)From the front page wikepedia "The record-depth Kola Borehole used non-rotary mud motor drilling to achieve a depth of over 12 000 meters (38,000 feet)." Cheers aussie in Stjørdal Norway.12.09.2007

The latest news (Wednesday, May 21, 2008) for the deepest oil well is Transocean jackup "GSF Rig 127" set a world record for the longest extended-reach well ever drilled at 40,320 feet (12,289 meters) MD (measured depth) with a 35,770-foot (10,902-meter) horizontal section. The well was drilled offshore Qatar in 36 days and incident-free. The new record of 7.6 miles is also the first well in the history of offshore drilling that exceeds 40,000 feet (12,191 meters). The well surpasses by approximately 2,000 feet the prior extended-reach record of 38,322 feet (11,680 meters) MD set by another drilling contractor with a land rig drilling at Sakhalin Island earlier this year.


Re rigs pulling 4-joint stands ("fourbles"), I made a slight edit to remove the "newer" description. In 1956 I roughnecked on a barge-mounted steam-powered rig in the swamps of South Lousiana that had a 189' derrick with 40' square rig floor. (The typical standard derrick of the era was 156' high with a 30' square floor.) It handled fourbles of Range 2 DP (or maybe thribbles of Rg 3 DP?) and my driller found out the hard way that you can't stand back this much 2-7/8" tubing without a belly board partway up in the derrick! Some modern offshore rigs may pull 120' stands, and other rigs used in effect the bottom 3/4 of a fourbles derrick to get the larger rig floor and racking space -- but only pulled thribbles. Irv (talk) 23:51, 18 January 2009 (UTC)

Well Costs[edit]

Those North Sea well costs from 1998 are out of date. I will look for some up to date stats. A dirty old semi-sub can cost $400k a day easily in the Central North Sea (water depths ~500 ft), while renting a snazzy 5th generation drill ship for use West of Shetland can easily be $750k a day. These are before you consider the costs of the service companies and equipment. The directional contractor can cost $100k a day on top, then theres the mud, skip & ship, casing, completions, etc. —Preceding unsigned comment added by (talk) 01:42, 2 February 2009 (UTC)

I'd take the whole section out -- it's better to say nothing than to give facts which are clearly wrong. Any objections?-- JakartaDean (talk) 06:56, 4 July 2009 (UTC)

Well Drilling page[edit]

There is a page at Well drilling, which covers much of the same material as this page. I'd reccomend merging the two. Tommfuller (talk) 13:10, 5 February 2009 (UTC)

Hmm I think it's possible, but it looks like both pages could be pretty large when they're more or less complete. If they were to be merged, I think well drilling should come into oil well, since this article is about various stages other than the actual drilling of the well. But if you do that, you're kind of ignoring water wells, which are significantly different and probably have an article of their own. I think a "see main article: well drilling" in the drilling section of this article is a good idea, but I don't really support an all out merge... TastyCakes (talk) 15:26, 5 February 2009 (UTC)

Agree with TastyCakes. There is apparently an article(s) on water wells as well.

There is also a mess with Well logging, Mud logging, and Mudlogger I have about got a handle on these, please see my notes at each and help if possible. Mydogtrouble (talk) 20:10, 12 May 2009 (UTC)

I think mud logging is a subset of well logging and the two shouldn't be merged. Merging mud logging into the well logging article would mean that all the other well logging subsets like sonic, neutron density, caliper, SP, resistivity etc would have to as well. I think all these articles are notable and substantial enough to have their own articles. Unless you were talking about the mud logging, mud logger and mud log articles, I agree those three should be merged, I think into mud logging. TastyCakes (talk) 20:14, 12 May 2009 (UTC)

Well logging, also called electric logging or wireline logging is entirely different from mud logging. Mud logging is done as part of the drilling process, continuously recording the different drilling parameters (speed of drilling, drilling torque, mud flow rate etc) against depth and the characterisitics of the drilled cuttings against depth while the well is being drilled. Well logging is done after the hole has been drilled (sometimes decades after the hole has been drilled), lowering different measurement tools (called sondes) down the well, uually on an armoured electrical wire (the 'wireline' or 'electric line') but sometimes on coiled tubing or on drill pipe, to measure the rock's properties like natural radioactivity, electrical restitivity, sonic travel time and so on. The only similarity between mudlogging & wireline logging is that both present infomation as a plot against depth- a 'log' in oilfield speak. Most Schlumberger engineers I know would be horrified to find what they do merged into mudlogging!! Nic Thwaites, Aberdeen —Preceding unsigned comment added by (talk) 16:54, 27 May 2009 (UTC)

Economic limit[edit]

I find this term confusing, especially the statement that a higher economic limit means a lower lifetime. What is the unit of measurement? Dollars per barrel? The article lists four variables that go into the equation. I would like to see the equation. Peter Chastain (talk) 13:57, 30 August 2009 (UTC)

I agree it's confusing, I've tried to make the section a bit clearer. Most importantly, I've pointed out that the economic limit is the production rate at which the oil stops making money. The formula would look something like this: Profit ($) = (Production (bbl) * Royalty Rate (%) * Tax Rate (%) * Oil Price ($/bbl)) - Operating costs ($).
When both sides of that equation are equal, you are at the economic limit (whatever your production is at that time). TastyCakes (talk) 17:07, 30 August 2009 (UTC)
Yes! That makes it very clear. Implicit in all of this is the concept that production eventually drops off. I edited the section a bit more to make that more explicit and to remove some redundancy. Thanks. Peter Chastain (talk) 22:21, 30 August 2009 (UTC)
Ya, that is implicit and it's good you pointed it out. TastyCakes (talk) 23:16, 30 August 2009 (UTC)

I feel like there needs to be some discussion about the fact that wells are drilled and capped even when they aren't at the limit of the economic limit. Obviously, if the well that the Deepwater Horizon was sealing for Oil well#Abandonment has been gushing like crazy for the last two months, the brand-new well wasn't "exhausted" or at its economic limit. Do oil companies drill wells and then "save them for later," so to speak? Alphachimera (talk) 15:44, 7 July 2010 (UTC)

Yes, wells are often drilled and in effect saved for later via completion. For example, the company may want to drill some appraisal wells to assess the field and try to figure out how to optimise the production, decide whether they need injection wells or even sell the field rather than produce from it themselves. There might not be any production infrastructure nearby if it's an exploration well and it can take time to figure out what to do about that. There are all sorts of reasons. It's not unusual. Sean.hoyland - talk 16:57, 7 July 2010 (UTC)
And sometimes, there will be more than one formation in a well that has oil and they will produce the bottom zone first and then the top when it is exhausted. In this case, all the infrastructure is in place and the work done (minus a perf job), the zone is just "waiting its turn". I think such reserves are usually called "being behind pipe" - proved-developed-nonproducing (PDNP). TastyCakes (talk) 17:06, 7 July 2010 (UTC)

I suggest putting some actual data into this section to illustrate the actual working of "economic limit" formula. In the US, on land, about 400,000 wells on land are producing less than a million barrels a day as I recall, with a cut off of about a barrel a day. The number of producing wells increased after 2000 as the price brought the strippers back into production. These are shallow wells without salt water incursion or pressure that are pumped cheaply. Most modern wells are either deep or include brine, so they are produced only as long as they have sufficient flow and someplace to inject the brine. Which switches the economics to the field production which might involve five producing wells and a hundred injection wells to create the pressure and flood the oil to the points of extraction. Mulp (talk) 19:25, 26 April 2011 (UTC)

Taxes and economic limit[edit]

RE: 02:29, 14 September 2009 Cerejota (talk | contribs) (23,142 bytes) (→Abandonment: in general, when taxes are raised, it affects pricing, not economic viability of the supply side - this makes no sense)

Cerejota's assertion may be correct in a macro-economic sense, but LaPella was merely talking about taxes as one of several expense items contributing to a well's daily operating cost. Irv (talk) 16:16, 14 September 2009 (UTC)

Taxes obviously affect economic limits. The oil price is set in a world market, while taxes are set at the national, state, or sometimes local level. When one jurisdiction raises taxes, that certainly will adversely affect the economics for oil producers in that jurisdiction.Plazak (talk) 16:50, 14 September 2009 (UTC)
That all might be true, but it is original research if not cited. In trying to find sources, all I found were partisan political and lobying sites. I am restoring the tag. Perhaps others will not fail were I did. My question still remains: how is it that taxes affect viability of a non-luxury commodity: they do affect pricing, but neither demand nor supply are affected to the point it lowers the economic viability of a given commodity - in this case the economic limit of a given oil field. I know of no taxes, anywhere in the world, in which individual wells are taxes. In fact, there are no taxes on oil production anywhere (unless you consider concession rates a tax, which would be a highly original interpretation), taxes are only levied upon customs or distribution of oil products, such as petrol... --Cerejota (talk) 09:05, 17 September 2009 (UTC)
Original wording restored and reference added. I'm surprised at the general lack of knowledge of basic economics, but I suppose that is why there is Wikipedia.Plazak (talk) 14:17, 17 September 2009 (UTC)
For a discussion of the Texas Severance Tax (4.6% of market value of crude oil produced), like an excise tax on the volume rather than the dollars, see Various incentive plans are mentioned; I don't know the current status of them. But the severance tax is one more expense item affecting the profit or loss of a given well. Other expense items can include royalties to the mineral owner (paid off the top whether or not the well is profitable), electricity for the pumping unit, a drum of emulsion breaker or corrosion inhibitor every week or so, salt water disposal costs (often a killer on marginal wells!), wages for the lease operator (who may look after a dozen or so wells), fuel for his pickup truck, a portion of the lease operating cost (e.g., maintaining the roads, painting the tank battery), and a share of the office overhead (which includes corporate income taxes). Once these exceed the revenue from oil sales, the well is no longer economic. None of this has anything to do with "non-luxury commodities"; it's just Econ 101 for the oil producer: he's losing money when expenses are greater than revenues.Irv (talk) 01:53, 18 September 2009 (UTC)

I took the provided source and expanded it - the source is for fields, not wells (in fact the formula takes into account that there might be multiple wells on fields), I also included the formulas, as I think it depends the knowledge. I provided an outside definition for one of the terms, which I found the most confusing, but perhaps the other terms need similar?--Cerejota (talk) 09:25, 25 September 2009 (UTC)

To say that the source is for the fields rather than wells is blatently false, as shown by the very terms being calculated (which are taken from the source):
is an oil well's economic limit in oil barrels per month (bbls/month).
is a gas well's economic limit in thousand standard cubic feet per month (MSCF/month).
Where is the term "field" in the above? The source explicity refers to "a gas well" and "an oil well". The reason that the calculation is done on a well-by-well basis is because a field or property may contain a mixture of both profitable and unprofitable wells. As supported by the cited source, whether you like it or not, that is the way it's done in the industry. I will correct the inexplicable refernces to "field" in the article. Plazak (talk) 03:36, 26 September 2009 (UTC)

Move? (May 2010)[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: page not moved: speedy close. Anthony Appleyard (talk) 16:14, 16 May 2010 (UTC)

Oil wellFossil-fuel well

  • See also Wikipedia:Categories_for_discussion/Log/2010 May 14#Category:Oil wells. User:Nopetro 08:23, 14 May 2010 (UTC)
  • Oppose - Nobody uses this term. Sean.hoyland - talk 11:00, 14 May 2010 (UTC)
  • Why? (There are hardly any google hits for this term.) Occuli (talk) 13:25, 14 May 2010 (UTC)
  • Oppose - I understand you are trying to resolve the issue with gas wells, but this can be fixed by making a separate gas well page, if it is warranted, or changing this to "petroleum well" or something, but then it is a less-used term.Qfl247 (talk) 13:45, 14 May 2010 (UTC)
  • Oppose "Oil and gas well" would be the way to go, if a change is really needed, but is a bit tricky for the singular title. Johnbod (talk) 13:28, 15 May 2010 (UTC)
  • Oppose Unnecessary neologism. Fletcher (talk) 15:02, 15 May 2010 (UTC)
  • Oppose Don't change a thing. The introductory paragraph describes both oil and gas wells just fine (most produce both substances), and Oil well is the generic term both in industry and with the public. Gas well redirects here anyway. Casey (talk) 15:11, 15 May 2010 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Requested move again (August 2010)[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: No. T. Canens (talk) 16:10, 7 August 2010 (UTC)

Oil wellfossil-fuel well —Is a natural-gas well an oil (petroleum) well?. Clearly, not. There are two alternatives, vreate a natural-gas well artivle or rename the oil well to reflect the real subject of fossil-fuel well (because the article treat both types of fosdil-fuel wells, the petroleum wells and the natural-gas wells). Hamiltha (talk) 09:54, 6 August 2010 (UTC)

Question - Please can you provide reliable sources that use the 'fossil fuel well' terminology to demonstrate who uses it and how it complies with WP:NAME ? I've not heard this terminology used in the Exploration and Production industry. Sean.hoyland - talk 10:28, 6 August 2010 (UTC)

  • oppose-speedy close - Not a real term. Natural gas comes from oil wells and other sources. Hamiltha doesn't seem to understand wp:NEO. Speedy close per NEO and above identical discussion. (talk) 20:07, 6 August 2010 (UTC)
  • An unregistered and anonymous user can not vote. In the definition of natural gas, you can see : "natural gas is a gas issuing from the earth's crust through natural openings or bored wells". [1]. "Gas well" redirects here, to the "oil well" article. There is a "completion (oil and gas wells)" in Wikipedia, so the name of "oil well" when treats the oil and gas wells is merely unsustainable. On the other hand, there are thousand of references for "fosil fuel drilling" (16,700 in Google) and also for fossil fuel exploration and natural gas drilling. ""Fossil fuel"" is used in a similar way in other concepts as "fossil fuel industry", "post-fossil fuel", ""fossil-fuel energy", "fossil-fuel-powered cars", ""fossil-fuel emissions" fossil fuel subsidies, "fossil fuel burner" and so on and so on. Hamiltha (talk) 01:16, 7 August 2010 (UTC)
    • Comment WP:VOTE - no users are supposed to vote, AFAIK. (talk) 05:05, 7 August 2010 (UTC)
    • Where do you get that idea from. I'm aware of no policy or guideline that says that. Indeed it is my believe that IP editors are allowed to !vote in nearly all discussions on wikipedia although the person closing the discussion should consider the fact that they're an IP when determining consensus. Dpmuk (talk) 09:26, 7 August 2010 (UTC)
  • Comment from the section above, this just failed a couple of months ago, and it was a resounding no, yet this new request reiterates the previous request. What's the point to this new request? (talk) 05:05, 7 August 2010 (UTC)
  • Oppose. Speedy close. No new arguments for the move. Beagel (talk) 05:30, 7 August 2010 (UTC)
Comment. If anything, oil and gas well may be considered. Beagel (talk) 05:41, 7 August 2010 (UTC)
  • Oppose. Speedy close – frivolous proposal so soon after it was resoundingly rejected. Occuli (talk) 15:44, 7 August 2010 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Taxes and economic limit (2)[edit]

Taxes and economic limit == It was mentioned tax implication is one reason why a well in its economic limit is anandoned. It is a normal accounting practice to make cost provision in anticipation of likelyhood of a well being abandoned in the near future and this cost is usually not allowed for tax purposes,in what ways should this cost provision be reported in order for it to be allowed for tax purposes? -(lbo) —Preceding unsigned comment added by (talk) 17:21, 16 January 2011 (UTC)

Estimating size of source[edit]

How are they able to estimate how much oil is available at any given site? --Enigma55 (talk) 03:21, 24 February 2011 (UTC)

There is a basic outline of the process at Petroleum_reservoir#Estimating_reserves. Sean.hoyland - talk 03:26, 24 February 2011 (UTC)

physical considerations[edit]

This article doesn't discuss any quantitative physics of oil wells at all, which predominate the literature on oil wells. elle vécut heureuse à jamais (be free) 06:19, 16 December 2011 (UTC)

I don't follow what you mean by quantitative physics of oil wells. Are you talking about borehole logging ? Sean.hoyland - talk 07:28, 16 December 2011 (UTC)
I'm talking about basic physical considerations during the life of a well, such as stress, hydraulic pressure formulas, leakoff and flowback. elle vécut heureuse à jamais (be free) 07:37, 16 December 2011 (UTC)
I see. Yes, you're right. It probably won't be fixed unless you do it yourself. The article doesn't seem to have many active editors. Sean.hoyland - talk 08:11, 16 December 2011 (UTC)

Unnecessary tags?[edit]

Why is there a Wiki Project United States and a Wiki Project Russia tag on the talk page? As for the article, I think the citation tag should be removed, because it appears as though there are sufficient citations now. Just a thought. Tboii99 02:13, 3 June 2012 (UTC)

Merger proposal[edit]

Oil well drilling problems has been suggested to be merged into this page. However, this could affect the impartiality of this article. Any opinions? smileguy91talk 23:04, 6 March 2013 (UTC)

Link correction: Oil Well Drilling Problems smileguy91talk 23:04, 6 March 2013 (UTC)

The article is copyvio anyway (obvious copy & paste). I'm simply redirecting; if there's anything worth salvaging, please do so. — kwami (talk) 02:04, 18 January 2014 (UTC)

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