A New Practical Approach To Evaluate Near Wellbore Formation Damage Parameters Based on Well Test Analysis for Gas Reservoir

2012 ◽  
Author(s):  
Melvin Kome ◽  
M.M. Amro ◽  
M.M. Hossain
Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jia Zhang ◽  
Shiqing Cheng ◽  
Shiying Di ◽  
Zhanwu Gao ◽  
Rui Yang ◽  
...  

Formation damage usually occurs in near-well regions for injection wells completed in offshore oilfields under the development of line drive patterns. However, current works on characterizing the damage by well test analysis were basically focused on using single-phase analogy to solve two-phase flow issues, resulting in errors on the diagnosis and interpretation of transient pressure data. In this paper, we developed a two-phase model to simulate the pressure transient behavior of a water injection well in a multiwell system. To solve the model more efficiently, we used the finite volume method to discretize partially differential flow equations in a hybrid grid system, including both Cartesian and radial meshes. The fully implicit Newton-Raphson method was also employed to solve the equations in our model. With this methodology, we compared the resulting solutions with a commercial simulator. Our results keep a good agreement with the solutions from the simulator. We then graphed the solutions on a log-log plot and concluded that the effects of transitional zone and interwell interference can be individually identified by analyzing specific flow regimes on the plot. Further, seven scenarios were raised to understand the parameters which dominate the pressure transient behavior of these flow regimes. Finally, we showed a workflow and verified the applicability of our model by demonstrating a case study in a Chinese offshore oilfield. Our model provides a useful tool to reduce errors in the interpretation of pressure transient data derived from injection wells located in a line drive pattern.


2012 ◽  
Vol 233 ◽  
pp. 401-404
Author(s):  
Jin Pang ◽  
Hong Liu ◽  
Xi Nan Yu

In view of the existing shortcomings of the analysis methods for the production system of conventional condensate gas well, the new method that adopts the non-steady gas reservoir seepage and the wellbore coupling has been proposed in this paper, in other words, the gas nozzle control, the wellbore flow and the reservoir seepage have been considered as the coupling entirety; the traditional nodal analysis has been combined with the well test analysis of non-steady seepage; the new production system analysis methods have been employed to discuss the characteristics of gas reservoir seepage, wellbore flow and gas reservoir boundary; at the same time, the changing trends of indicators in the development process have been also analyzed. Afterwards, the coordination state and the changes of parameters of the production system can be predicted in different production methods and different times. And the better results can be obtained through the application evaluation of YK1.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Xiao-Ping Li ◽  
Ning-Ping Yan ◽  
Xiao-Hua Tan

This paper presents a study of characteristic value method of well test analysis for horizontal gas well. Owing to the complicated seepage flow mechanism in horizontal gas well and the difficulty in the analysis of transient pressure test data, this paper establishes the mathematical models of well test analysis for horizontal gas well with different inner and outer boundary conditions. On the basis of obtaining the solutions of the mathematical models, several type curves are plotted with Stehfest inversion algorithm. For gas reservoir with closed outer boundary in vertical direction and infinite outer boundary in horizontal direction, while considering the effect of wellbore storage and skin effect, the pseudopressure behavior of the horizontal gas well can manifest four characteristic periods: pure wellbore storage period, early vertical radial flow period, early linear flow period, and late horizontal pseudoradial flow period. For gas reservoir with closed outer boundary both in vertical and horizontal directions, the pseudopressure behavior of the horizontal gas well adds the pseudosteady state flow period which appears after the boundary response. For gas reservoir with closed outer boundary in vertical direction and constant pressure outer boundary in horizontal direction, the pseudopressure behavior of the horizontal gas well adds the steady state flow period which appears after the boundary response. According to the characteristic lines which are manifested by pseudopressure derivative curve of each flow period, formulas are developed to obtain horizontal permeability, vertical permeability, skin factor, reservoir pressure, and pore volume of the gas reservoir, and thus the characteristic value method of well test analysis for horizontal gas well is established. Finally, the example study verifies that the new method is reliable. Characteristic value method of well test analysis for horizontal gas well makes the well test analysis process more simple and the results more accurate.


Author(s):  
Muhammad Handis Maulana ◽  
Muhammad Taufiq Fathaddin ◽  
Hari Karyadi Oetomo

<p><em>Wells X-1 is a gas condensate well which located in lapangan X, Sulawesi Island. At well X-1 well test was conducted using pressure build up, where the analysis was conducted with objective to determine the reservoir characteristic of X-1 wells such as permeability, skin, flow efficiency and investigation radius. In the pressure build up test, the horner plot and derivation analysis using pseudo pressure and P2 approaches were applied with the gas well X-1 has a reservoir pressure of 2555 psia. The analysis is done using saphir 3.20 and Ms.Excel software where the results of the counsel to see if there is any possibility of formation damage. X-1 is also known as homogeneous with a fault boundary present in the fault located at a certain distance from the well X-1 in which the fault is only one direction from the reservoir. The pressure derivative plot analysis was conducted with two methods such as two-point method and three-point method, where the result of the overlay of the derivative curve corresponds to the deviation of the calculation result method which is less than 10%. The horner plot analysis is also done with the ψ(P) pseudo pressure and P2 approach which is the result of horner plot analysis using pseudo pressure ψ(P) pseudo pressure in saphir 3.20 obtained the slope (m), permeability, and skin values respectively were 3.22432E + 5 psi2/cp, 132 mD, and 21.6, whereas Ms.Excel results obtained the price of slope (m), permeability, and skin respectively were 320890.61 psi2/cp, 134.83 mD, and 21.1. To analyze the horner plot using the P2 approach at saphir 3.20 the value of slope (m), permeability, and skins values respectively were 5495.07 psi2/cp, 125 mD, and 21.3 and for the results of Ms. Excel the price of slope (m), permeability, and skin respectively were 5451.66 psi2/cp, 147,29 mD, and 20,1. Positive skin results in both methods of horner plot and derivative plot indicate the well is damaged and need to be stimulated</em><em>.</em></p>


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