Shale-Oil Development Prospects: The Role of Shale-Gas in Developing Shale-Oil

Round 1

Reviewer 1 Report

I found the paper very interesting and insightful on the problem of future plans on petroleum reservoirs and policies (and politics perhaps). I would like the authors to check my comments below and provide some enhancements on the manuscript. one major question is that why the focus was solely on "shale reservoirs" and not other types of reservoirs as well.

 

- Please explain the difference between “shale-oil resource” and “conventional petroleum reservoir” (page 2, second paragraph), as shale reservoir is itself a conventional reservoir.

- It was not very clear why there is a “competition” (if I am allowed to use this term) between shale-oil and shale-gas. Please provide more explanation on it. I want to say, is it on the physiological point of view/expectations searching for oil and finding gas, or the loss comes based on the technical methods used in the two cases, i.e. is real cost due to exploration/planning.

- Following my previous comment, it would be interested to be included some statistics/values of oil and gas prices as well as exports. Apart from USA, as I know, Australian economy is also very active in oil/gas industries and also China has quite many petroleum reservoirs. Please provide some comparisons, if applicable.

- Note (7), bottom of page 2: Please correct as “silver”.

- It would be interested to briefly explain some differences of conventional and unconventional gas (and oil) resources/developments.

- Following one of my previous questions, as the paper was set predominantly based on the question if the exploration should start first for gas or oil, it could be useful to provide the cost losses if it goes the other way around and vice versa (for example based on real examples or with a more “academic” estimation).

- Though shale is the most common rock on earth and petroleum reservoir, there are also other types of reservoirs (e.g. sandstones). Why the manuscript/research excluded other resources?

- Examples were given on improvement in oil-gas-development in USA over the previous years. It could be interested to show also some more global trends as there are also other players in market (e.g. Arabian countries, China, Australia etc) to get some more general picture, though USA has certainly a core role in this industry.

- Hydraulic fracturing increases the “fractures” thus the secondary permeability through rocks which advance petroleum extraction processes. How crucial is this process to be precisely simulated? i.e. how crucial is the mechanics-physics of fracture rocks and their simulation in the petroleum industry, if we could put numbers to this.

- The data in Table 1 were very interesting to see which also demonstrate the influence of future petroleum production on geopolitical strategies. I think it would worth some further discussion on it. It also would be interesting to see not only consumption but changes/rates of consumption, i.e. how much different countries are changing the consumption over the previous years, which also may be important information.

- Though the article is focused on petroleum reservoirs/developments/economic aspects, it worth comparing briefly the advantages/disadvantages with nuclear plant industries.

- Based on the information and discussion in the main text, I think the conclusions section could be enhanced / strengthened with more highlights on the new insights from the study.

 

Author Response

See attached reply for Reviewer 1

Author Response File: Author Response.docx

Reviewer 2 Report

I would like to thank the authors for delivering their manuscript on an interesting topic - exploitation of shale-rock fuel resources. In particular the authors examine how the different exploration/production scenarios between shale-oil and shale-gas have been applied in the U.S. considering the local conditions (technology, infrastructure, need/price of fossil fuel and h/c energy resources); they do so in an effort to draw conclusions on the prospects or the potential difficulties to be met in attempts for shale-oil developments in other countries across the globe.

The topic and text writing triggered my interest. After a few pages though I was not able to find the point the authors wanted to make -- or I could not grasp it directly. The authors clearly emphasize on the differences between shale-gas and shale-oil exploration and production activities. They provide a basic overview on the characteristics of shale formations, necessary technology and investments in technology and infrastructure (both upstream and downstream). Nevertheless I missed the point of the manuscript as well as its added value, the target readers, new findings of that article, conclusions etc.

The long discussion on the topic /subject (where the bets are higher, in shale-oil or shale-gas), disseminates new knowledge to the readers (shale-gas is easier to find than shale-oil, nevertheless investments in infrastructure, e.g. pipeline network, are required). Yet  it is difficult to build on that knowledge, e.g. by creating a rational framework over which one could draw predictions on future prospects of searching, detecting, exploring and producing from the undiscovered /untapped shale formations around the globe.    

The text is very well written in terms of use of English language, grammar and syntax; it is easy to read -- albeit it is difficult to grasp the rationale.

In terms of typos and layout, I would suggest to improve the Table in the manuscript (compress /reduce its size; if possible keep in one page otherwise use Word Table properties to repeat headers in consecutive pages). Still referring to that Table, I could not find (in the legend and/or the main text) any indication of any kind of norm and/or threshold value for identifying those countries that the authors expect them not to proceed with exploitation of shale-resources. It is also unclear to me why and how some cells are shaded (a legend and the end of the Table would be helpful).

The conclusions should be more clear and explicit.

The literature is extensive.

I have highlighted a few suggestions for improvement in the manuscript (mainly typos of minor importance) - these are only suggestions.

In conclusion, I am positive on publishing an improved version of the  manuscript.

Author Response

Please see reply for reviewer 2

Author Response File: Author Response.docx