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www.chevron.ro/
Facem aceste aprecieri avnd n vedere beneficiile pe scar larg realizate din proiectele
de exploatare a gazelor din ist n Statele Unite. La ora actual, uropa import cca. !"# dingazele pe care le consum $sursa% &gen'ia (nterna'ional pentru nergie). Se estimeaz c
importurile vor crete la *+# pn n anul "+", datorit cererii tot mai mari, legisla'iei de mediu
tot mai exigente i declinului produc'iei din zcmintele de gaze existente.
Fracturarea Hidraulic
-ezvoltarea condi'iilor de exploatare necesit o tenic de fracturare idraulic, o tenologie
consacrat, sigur i cu bune rezultate utilizat n peste / milion de sonde , nc din /0!".
1rocesul implic pomparea unui amestec de fracturare compus din ap, nisip i mici cantit'i de
aditivi printr2o sond, care ptrund n strat prin perfora'iile coloanei de fora3, crend fisuri.
&ceste fisuri sunt umplute cu nisip pentru a determina gazele s ias la suprafa . &ditivii care se
utilizeaz n acest proces sunt aceeai care se folosesc n opera'iunile conven'ionale i sunt
reglementa'i n statele membre U. -escoperirile pot fi evaluate, n faza de exploatare
experimental, prin fracturarea a mici zone de testare cu sonde verticale i prin monitorizarea
debitului de gaze. -up trecerea la exploatarea comercial, companiile foreaz sonde orizontale
n roca purttoare de gaze i fractureaz istul pe ntrega arie de dezvoltare a acestuia.
Protec ia apelor
4evron prote3eaz acviferele subterane de fluidele de fracturare i de gaze prin cptuirea sau
5cmuirea5 sondelor cu straturi multiple de o'el i ciment. 6estate pentru rezisten'a la presiune,
coloanele rezist pe toat durata de via' a sondei. Fluidele de fracturare idraulic sunt de obicei
utilizate la adncimi de peste sau + 7ilometri sub nivelul acviferului, fiind separate de acesta
prin straturi multiple de roc impermeabil.
-up fracturare, apa uzat care iese la suprafa' este evacuat n mod adecvat printr2o instala'ie
certificat, este tratat i reutilizat sau, n unele cazuri, este rein3ectat n straturi de roc mai
adnci.
ttp%88en.9i7ipedia.org89i7i8File%(&:;orld:Sale:
8/10/2019 Curs 5' - Gaze de sist
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(llustration of sale gas compared to oter t>pes of gas deposits
http://upload.wikimedia.org/wikipedia/commons/b/bb/GasDepositDiagram.jpg8/10/2019 Curs 5' - Gaze de sist
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What is Hydraulic Fracturing?
Hydraulic fracturing is a procedure that can increase the flow of oil or gas from a well. It is done by pumping liquids down a well into subsurface rock units under pressures thatare high enough to fracture the rock. The goal is to create a network of interconnected fractures that will serve as pore spaces for the movement of oil and natural gas to the wellbore.
Hydraulic fracturing combined with horizontal drillinghas turned previously unproductive organic-rich shales into the largest natural gas fields in the world. The arcellus !hale"
#arnett !haleand#akken $ormationare e%amples of previously unproductive rock units that have been converted into fantastic gas or oil fields by hydraulic fracturing.
ttp%88geolog>.com8articles8>draulic2fracturing8
+
http://geology.com/articles/horizontal-drilling/http://geology.com/articles/horizontal-drilling/http://geology.com/articles/marcellus-shale.shtmlhttp://geology.com/articles/marcellus-shale.shtmlhttp://geology.com/research/barnett-shale-gas.shtmlhttp://geology.com/research/barnett-shale-gas.shtmlhttp://geology.com/usgs/bakken-formation-oil.shtmlhttp://geology.com/usgs/bakken-formation-oil.shtmlhttp://geology.com/usgs/bakken-formation-oil.shtmlhttp://geology.com/articles/hydraulic-fracturing/http://geology.com/articles/horizontal-drilling/http://geology.com/articles/marcellus-shale.shtmlhttp://geology.com/research/barnett-shale-gas.shtmlhttp://geology.com/usgs/bakken-formation-oil.shtmlhttp://geology.com/articles/hydraulic-fracturing/8/10/2019 Curs 5' - Gaze de sist
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ttp%88999.gandul.info8financiar8scandalul2pungilor2de2bogatie2de2sub2unul2dintre2cele2mai2
sarace23udete2din2tara2ce2cauta2americanii2la2barlad20H+/IHI
-up spusele lor $4evron), fluidele folosite n cadrul procedeului de fracturare idraulic sunt
utilizate la adncimi ciar de peste 2 + 7ilometri fa' de nivelul acviferului, fapt ce l separ deel prin intermediul mai multor straturi de roc impermeabil.
5-up fracturare, sondele care produc gaze de ist debiteaz i cantit'i reduse de ape de
zcmnt cu mineraliza'ie crescut, care fie sunt deversate la sta'ii autorizate de tratare, conformreglementrile legale, fie sunt tratate i reutilizate sau rein3ectate n straturile de roc mai adnci,
n sonde de in3ec'ie5, se mai arat n cadrul documentelor companiei.
?eprezentan'ii 4evron sus'in, de asemenea, c n scopul prote3rii mediului ncon3urtor
realizeaz o serie de studii cu privire la impactul asupra mediului ncon3urtor i asupra snt'ii.
n ce const metoda fracturrii hidraulice
6enologia fracturrii idraulice este utilizat nc din anul /0!" de peste un milion de sonde.1entru realizarea ei se pompeaz un amestec compus din ap, nisip i cantit'i mici de aditivi
printr2o sond, conform datelor oficiale cu privire la activit'ile 4evron n uropa.
&mestecul ptrunde apoi prin 5perforaturile colanei de fora35 i creeaz fisuri ce sunt umplute cunisip pentru a face gazele s curg. ?eprezentan'ii 4evron sus'in c aditivii utiliza'i n cadrul
fracturrii idraulice sunt folosi'i i n opera'iunile conven'ionale i sunt reglementa'i de ctrestatele membre ale Uniunii uropene.
Extragerea gazelor de ist
Urmtoarea etap a procedeului reprezint evaluarea descoperirilor fcute n cadrul fazei deexploatare experimental, care este realizat prin fracturarea unor zone mici de testare cu
a3utorul unor sonde verticale i prin monitorizarea debitului de gaze ob'inut.
Jdat cu trecerea la exploatarea comercial a gazelor de ist roca este forat cu o serie de sondeorizontale i este fracturat istul pe toat suprafa'a lui.
Chemical Use In Hydraulic Fracturing
ttp%88fracfocus.org89ater2protection8drilling2usage
&hemicals serve many functions in hydraulic fracturing. $rom limiting the growth of bacteria to preventing corrosion of the well casing" chemicals areneeded to insure that the fracturing 'ob is effective and efficient.
The number of chemical additives used in a typical fracture treatment depends on the conditions of the specific well being fractured. ( typical fracturetreatment will use very low concentrations of between ) and *+ additive chemicals" depending on the characteristics of the water and the shaleformation being fractured. ,ach component serves a specific" engineered purpose. $or e%ample" the predominant fluids currently being used forfracture treatments in the gas shale plays are waterbased fracturing fluids mi%ed with frictionreducing additives called slickwater. The addition offriction reducers allows fracturing fluids and sand" or other solid materials called proppants" to be pumped to the target zone at a higher rate andreduced pressure than if water alone were used. In addition to friction reducers" other additives include biocides to prevent microorganism growth andto reduce biofouling of the fractures0 o%ygen scavengers and other stabilizers to prevent corrosion of metal pipes0 and acids that are used to removedrilling mud damage within the nearwellbore area.
$luids are used to create the fractures in the formation and to carry a propping agent typically silica sand which is deposited in the induced fractures
to keep them from closing up. The chart below taken fromodern !hale 1as 2evelopment in the 3nited !tates ( 4rimerdemonstrates the volumetricpercentages of additives that were used for a ninestage hydraulic fracturing treatment of a $ayetteville !hale horizontal well.
I
http://www.gandul.info/financiar/scandalul-pungilor-de-bogatie-de-sub-unul-dintre-cele-mai-sarace-judete-din-tara-ce-cauta-americanii-la-barlad-9431545http://www.gandul.info/financiar/scandalul-pungilor-de-bogatie-de-sub-unul-dintre-cele-mai-sarace-judete-din-tara-ce-cauta-americanii-la-barlad-9431545http://fracfocus.org/water-protection/drilling-usagehttp://fracfocus.org/node/93http://fracfocus.org/node/93http://fracfocus.org/node/93http://www.gandul.info/financiar/scandalul-pungilor-de-bogatie-de-sub-unul-dintre-cele-mai-sarace-judete-din-tara-ce-cauta-americanii-la-barlad-9431545http://www.gandul.info/financiar/scandalul-pungilor-de-bogatie-de-sub-unul-dintre-cele-mai-sarace-judete-din-tara-ce-cauta-americanii-la-barlad-9431545http://fracfocus.org/water-protection/drilling-usagehttp://fracfocus.org/node/938/10/2019 Curs 5' - Gaze de sist
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The makeup of fracturing fluid varies from one geologic basin or formation to another.
,valuating the relative volumes of the components of a f racturing fluid reveals the relatively small volume of additives that are present. The additivesdepicted on the right side of the pie chart represent less than 5.67 of the total fluid volume. 8verall the concentration of additives in most slickwaterfracturing fluids is a relatively consistent 5.67 to +7 with water making up 9:7 to 99.67.
#ecause the makeup of each fracturing fluid varies to meet the specific needs of each area" there is no onesizefitsall formula for the volumesfor each additive. In classifying fracturing fluids and their additives it is important to realize that service companies that provide these additives havedeveloped a number of compounds with similar functional properties to be used for the same purpose in different well environments. The differencebetween additive formulations may be as small as a change in concentration of a specific compound.
(lthough the hydraulic fracturing industry may have a number of compounds that can be used in a hydraulic fracturing fluid" any single fracturing 'obwould only use a few of the available additives. $or e%ample" the chart shown above" represents *+ additives used" covering the range of possiblefunctions that could be built into a fracturing fluid.
=arcellus sale fragments. 1otograp% -aniel &c7er8 (mages
Shale gasisnatural gasformed from being trapped 9itin saleformationsK/. Sale gas asbecome an increasingl> important source of natural gas in te United States over te past decade,
and interest as spread to potential gas sales in te rest of te 9orld. Jne anal>st expects salegas to suppl> as muc as alf te natural gas production in Cort &merica b> "".KKdead link
!
http://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Shalehttp://en.wikipedia.org/wiki/Shale_gas#cite_note-0%23cite_note-0http://en.wikipedia.org/wiki/Shale_gas#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/Shale_gas#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/Wikipedia:Link_rothttp://en.wikipedia.org/wiki/Wikipedia:Link_rothttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Shalehttp://en.wikipedia.org/wiki/Shale_gas#cite_note-0%23cite_note-0http://en.wikipedia.org/wiki/Shale_gas#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/Wikipedia:Link_rot8/10/2019 Curs 5' - Gaze de sist
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Some anal>sts expect tat sale gas 9ill greatl> expand 9orld9ide energ> suppl>.K+& stud> b>
teEa7er (nstitute of 1ublic 1olic>at?ice Universit>concluded tat increased sale gasproduction in te US and 4anada could elp prevent ?ussia and 1ersian result in te release of
more greenouse gases tan conventional natural gas,K!KM
, altoug oter studiesK*
avecriticized one of tese for rel>ing on implausibl> ig lea7age rates and misstating te global
9arming potential of metane.K0Jter recent studies point to ig decline rates of some salegas 9ells as an indication tat sale gas production ma> ultimatel> be muc lo9er tan is
currentl> pro3ected.K/"
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http://en.wikipedia.org/wiki/Shale_gas#cite_note-2%23cite_note-2http://en.wikipedia.org/wiki/Shale_gas#cite_note-2%23cite_note-2http://en.wikipedia.org/wiki/Baker_Institute_of_Public_Policyhttp://en.wikipedia.org/wiki/Baker_Institute_of_Public_Policyhttp://en.wikipedia.org/wiki/Rice_Universityhttp://en.wikipedia.org/wiki/Rice_Universityhttp://en.wikipedia.org/wiki/Shale_gas#cite_note-3%23cite_note-3http://en.wikipedia.org/wiki/Shale_gas#cite_note-3%23cite_note-3http://en.wikipedia.org/wiki/Barack_Obamahttp://en.wikipedia.org/wiki/Shale_gas#cite_note-4%23cite_note-4http://en.wikipedia.org/wiki/Shale_gas#cite_note-5%23cite_note-5http://en.wikipedia.org/wiki/Shale_gas#cite_note-6%23cite_note-6http://en.wikipedia.org/wiki/Shale_gas#cite_note-7%23cite_note-7http://en.wikipedia.org/wiki/Shale_gas#cite_note-8%23cite_note-8http://en.wikipedia.org/wiki/Shale_gas#cite_note-8%23cite_note-8http://en.wikipedia.org/wiki/Shale_gas#cite_note-9%23cite_note-9http://en.wikipedia.org/wiki/Shale_gas#cite_note-2%23cite_note-2http://en.wikipedia.org/wiki/Baker_Institute_of_Public_Policyhttp://en.wikipedia.org/wiki/Rice_Universityhttp://en.wikipedia.org/wiki/Shale_gas#cite_note-3%23cite_note-3http://en.wikipedia.org/wiki/Barack_Obamahttp://en.wikipedia.org/wiki/Shale_gas#cite_note-4%23cite_note-4http://en.wikipedia.org/wiki/Shale_gas#cite_note-5%23cite_note-5http://en.wikipedia.org/wiki/Shale_gas#cite_note-6%23cite_note-6http://en.wikipedia.org/wiki/Shale_gas#cite_note-7%23cite_note-7http://en.wikipedia.org/wiki/Shale_gas#cite_note-8%23cite_note-8http://en.wikipedia.org/wiki/Shale_gas#cite_note-9%23cite_note-9
