Lime piles, which essentially consist of holes in the ground filled with lime, has been used two distinct purposes 1. For the soil treatment ( mainly treatment of clay soil) in situ and 2. It supported load transfer platform to increase the strength. So, you may use as soil improvement as well as remediation of contaminated clay soil. But I am not sure whether oil contaminated soil can be reclaimed.....

I do not believe you are going to get any quick fix for oil contaminated soil. I am pretty certain that if the soil is well aerated and the climate is not too dry (near Baghdad?) the oil will eventually oxidize either by microbial action or simply mineral processes. However it will not be fast enough to save a contaminated farm before the farmer starves (or maybe dies of old age). This will not happen if the soil is very compacted. The only use I can imagine for lime on oil contaminated soils is for it to be well spread out and mixed in for correcting extreme acidity so that various organisms (maybe even plants) which assist with keeping the soil aerated and microbial active) can do better there. However that is only if the soil is less than say, pH6.5.

If you have already started, I hope I am wrong. but... Good luck.

We use lime materals for acid soil remediation and for radionuclide contaminated soils in the Chtrnobyl area.

V. M. Starodubtsev has a very good point. Lime and, depending on the soil chemistry, gypsum are great for displacing metallic pollution ions, radioactive or whatever from the soil particles via ion exchange. However I am not sure if there are any positively charged ions involved in oil contamination. I will leave it to others to tell us if there are any acids to neutralize or if there are any ionic components to oil contamination which might allow the lime to make a significant direct contribution.

A paper by Andrew John Weightman "Diversity of bacteria in a petroleum-contaminated soil spiked with polycyclic aromatic hydrocarbons" might relate to the biological processes involved. Just search his name above. Likewise any papers cited there by him might be pertinent.

check these links..

http://www.britishlime.org/documents/BLATechnicalData4.pdf

https://nepis.epa.gov/Exe/ZyNET.exe/60000LQ7.TXT?ZyActionD=ZyDocument&Client=EPA&Index=2006+Thru+2010&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%5CIndex%20Data%5C06thru10%5CTxt%5C00000001%5C60000LQ7.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL

https://books.google.ca/books?id=2yTgg4qT89YC&pg=PA473&lpg=PA473&dq=Is+lime+pile+used+for+soil+improvement+or+remediation+of+contaminated+soil+or+both?&source=bl&ots=iLgF-0V5UP&sig=gTEz6fSwi55glsOdfZu7GiBVBAk&hl=en&sa=X&ved=0ahUKEwjLy8SAkenTAhXlzIMKHUsZCKEQ6AEITjAI#v=onepage&q=Is%20lime%20pile%20used%20for%20soil%20improvement%20or%20remediation%20of%20contaminated%20soil%20or%20both%3F&f=false

 Thank you J. C. Tarafdar  for you kind reply and interesting information, but the objective of research to improve the geotechnical properties of soil not to be used for agricultural purposes. 

Dear Lewis Maccarter, I am looking for deep soil improvement of geotechnical properties of soil through applying the concepts of sustainability. Thank you for interesting information. I am trying to know if lime is active in remediation of oil contamination or not, there are some references referred that. 

lime may not provide a remedy to soil that is oil; contaminated because lime is an alkali and one would expect it to neutralize acid soil but oil does not have properties of acids. In general lime improves soil structure and also neutralize acid soil that is why farmers would add it to the soil.

Thank you Maligana

thank you  so much about your openions, but after  the progress of the research, it was found that remadiation  of  contaminated soil with heavy crude oil by using lime pile technique gave better results than improving the intact soil itself . The increasing in  the pollutant concentration causes grater effect on geotechnical properties of soil. while  the percentage of remadiation increse with increase the contaminant concentration, because the harmful was greater.Therfore  the percentage of  treatment is more than soil improving with the same technique, lead. Thank you again for your opinion.