Analysis and Application of Horizontal Well Test in Low Permeability Porous Carbonate Reservoir

Round 1

Reviewer 1 Report

1.        The introduction can be significantly improved. “80 % of the oil and gas production in this area comes from carbonate” requires a reference. 

2.        The literature review required significant revision. These mentioned references should be commented and compared to show its connection of this study.

3.        What is the formation pressure and in situ oil viscosity ?

4.        “By comprehensive comparison, horizontal wells are more suitable for the development of low permeability carbonate rocks” is insufficient or incorrect! You may explain the comprehensive comparison results briefly.

5.        It seemed the current method apply to both carbonate and sandstone reservoirs. Where is “carbonate” in the manuscript?

6.        Every symbol should be explained. For instance, what is K(___), Z^*, H^*, etc.

7.        Fig.4 legends should be given.

8.        Fig.9 indicated that different trends exist. Why?

9.        Many figures were not mentioned. Pls check!

10.     How was Figure 11 produced?  

Author Response

Dear Professor，

my specific modifications and answers are in the attachment.Please see the attachment.

With best wishes.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Zhao et al. provided an interesting study regarding well test analysis in carbonate reservoirs. Sufficient work has been performed by the authors. The article could be considered to be accepted with Detailed comments are listed below for the authors’ consideration.

1.     Kindly include more take-home messages with number in the abstract

2.     Kindly include some more literature regarding low permeability reservoirs. The article below is suggested to be consulted as a starting point. Permeability measurement of the fracture-matrix system with 3D embedded discrete fracture model. Petroleum Science 2022.

3.     Figure 3 kindly mention the sources if there is any.

4.     Kindly add the axis titles in the x and y axes

Author Response

Dear Professor，

my specific modifications and answers are in the attachment.Please see the attachment.

With best wishes.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

it is particularly important to combine 10 well test interpretation with production dynamic analysis to diagnose the main control factors and 11 production characteristics of this type of reservoir. In this paper, the point source function is used 12 to obtain the pressure variation function of horizontal well in infinite formation with upper and 13 lower closed boundary. The difference between the horizontal well test curve of A reservoir and the 14 typical horizontal well test curve is compared and analyzed, and the abnormal well test curve of 15 horizontal wells is characterized by a linear flow phase with a slope of 1/3 or 1/4.

 

I am satisfied with the revison except one point: There are no conclusions! 

Author Response

Professor，

Thank you for your guidance. I have revised it in the latest version. Please refer to the attachment for details.

Author Response File: Author Response.docx