A Semi-Analytical Model for Predicting Horizontal Well Performances in Fractured Gas Reservoirs With Bottom-Water and Different Fracture Intensities

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yongsheng Tan ◽  
Haitao Li ◽  
Xiang Zhou ◽  
Beibei Jiang ◽  
Yongqing Wang ◽  
...  

Numerical simulation and prediction studies on horizontal well performances in gas reservoir are foundation for optimizing horizontal well completion process. To gain more understanding on this theory, a steady-state reservoir model coupling with wellbore is developed in the fractured gas reservoirs with bottom-water and different fracture intensities to predict the horizontal well performances. Based on the equivalent flow assumption, the fractured porous medium is transformed into anisotropic porous medium so that the gas reservoir flow model can be developed as a new model that incorporates formation permeability heterogeneity, reservoir anisotropy, and gas reservoir damage. The wellbore flow model which considers pressure drops in the tubing is applied. We compare this paper model solutions for inflow profile along the well to the numerical solutions obtained from a commercial simulator (ECLIPSE 2011), and the result shows a very good agreement. Moreover, sensitive analysis, in terms of various linear densities of fractures, matrix permeability, fracture width, and wellbore pressure drop, is implemented. The results show that the new model developed in this study can obtain a more practical representation to simulate the horizontal wells performance in fractured gas reservoir with different fracture intensities and bottom-water, thus can be used to optimize the parameters in horizontal well completion of fractured gas reservoirs with different fracture intensities and bottom-water.

2020 ◽  
Vol 213 ◽  
pp. 02009
Author(s):  
Quan Hua Huang ◽  
Xing Yu Lin

Horizontal Wells are often used to develop condensate gas reservoirs. When there is edge water in the gas reservoir, it will have a negative impact on the production of natural gas. Therefore, reasonable prediction of its water breakthrough time is of great significance for the efficient development of condensate gas reservoirs.At present, the prediction model of water breakthrough time in horizontal Wells of condensate gas reservoir is not perfect, and there are mainly problems such as incomplete consideration of retrograde condensate pollution and inaccurate determination of horizontal well seepage model. Based on the ellipsoidal horizontal well seepage model, considering the advance of edge water to the bottom of the well and condensate oil to formation, the advance of edge water is divided into two processes. The time when the first water molecule reaches the bottom of the well when the edge water tongue enters is deduced, that is, the time of edge water breakthrough in condensate gas reservoir.The calculation results show that the relative error of water breakthrough time considering retrograde condensate pollution is less than that without consideration, with a higher accuracy. The example error is less than 2%, which can be effectively applied to the development of edge water gas reservoir.


2015 ◽  
Author(s):  
Fen Yang ◽  
Larry K. Britt ◽  
Shari Dunn-Norman

Abstract Since the late 1980's when Maersk published their work on multiple fracturing of horizontal wells in the Dan Field, the use of transverse multiple fractured horizontal wells has become the completion of choice and become the “industry standard” for unconventional and tight oil and tight gas reservoirs. Today approximately sixty percent of all wells drilled in the United States are drilled horizontally and nearly all of them are multiple fractured. Because a horizontal well adds additional cost and complexity to the drilling, completion, and stimulation of the well we need to fully understand anything that affects the cost and complexity. In other words, we need to understand the affects of the principal stresses, both direction and magnitude, on the drilling completion, and stimulation of these wells. However, little work has been done to address and understand the relationship between the principal stresses and the lateral direction. This paper has as its goal to fundamentally address the question, in what direction should I drill my lateral? Do I drill it in the direction of the maximum horizontal stress (longitudinal) or do I drill it in the direction of the minimum horizontal stress (transverse)? The answer to this question relates directly back to the title of this paper and please "Don't let your land man drive that decision." This paper focuses on the horizontal well's lateral direction (longitudinal or transverse fracture orientation) and how that direction influences productivity, reserves, and economics of horizontal wells. Optimization studies using a single phase fully three dimensional numeric simulator including convergent non-Darcy flow were used to highlight the importance of lateral direction as a function of reservoir permeability. These studies, conducted for both oil and gas, are used to identify the point on the permeability continuum where longitudinal wells outperform transverse wells. The simulations compare and contrast the transverse multiple fractured horizontal well to longitudinal wells based on the number of fractures and stages. Further, the effects of lateral length, fracture half-length, and fracture conductivity were investigated to see how these parameters affected the decision over lateral direction in both oil and gas reservoirs. Additionally, how does completion style affect the lateral direction? That is, how does an open hole completion compare to a cased hole completion and should the type of completion affect the decision on in what direction the lateral should be drilled? These simulation results will be used to discuss the various horizontal well completion and stimulation metrics (rate, recovery, and economics) and how the choice of metrics affects the choice of lateral direction. This paper will also show a series of field case studies to illustrate actual field comparisons in both oil and gas reservoirs of longitudinal versus transverse horizontal wells and tie these field examples and results to the numeric simulation study. This work benefits the petroleum industry by: Establishing well performance and economic based criteria as a function of permeability for drilling longitudinal or transverse horizontal wells,Integrating the reservoir objectives and geomechanic limitations into a horizontal well completion and stimulation strategy,Developing well performance and economic objectives for horizontal well direction (transverse versus longitudinal) and highlighting the incremental benefits of various completion and stimulation strategies.


Author(s):  
Tao Zhu ◽  
Jing Lu

Many gas reservoirs are with bottom water drive. In order to prevent or delay unwanted water into the wellbore, the producing wells are often completed as partially penetrating vertical wells, and more and more horizontal wells have been drilled in recent years in bottom water drive gas reservoirs to reduce water coning and increase productivity. For a well, non-Darcy flow is inherently a near wellbore phenomenon. In spite of the considerable study that non-Darcy behavior of fully penetrating vertical wells, there has been no study of a partially penetrating vertical well or a horizontal well in a gas reservoir with bottom water drive. This paper presents new binomial deliverability equations for partially penetrating vertical gas wells and horizontal gas wells, assuming that only radial flow occurs in the near wellbore non-Darcy’s flow domain. The inflow performance of a vertical gas well is compared with that of a horizontal gas well. The proposed equations can account for the advantages of horizontal gas wells.


2012 ◽  
Vol 616-618 ◽  
pp. 674-679
Author(s):  
Ke Liu Wu ◽  
Xiang Fang Li ◽  
Xiao Ting Gou

According to material balance principle, gas/water bearing height in gas reservoir with bottom water could be deduced. Additionally, sweep efficiency could be approximately determined, then based on the equivalent flowing resistance method and critical vertical velocity of bottom water drive, computational model of Critical Producing Pressure Drop during the development of gas reservoir with bottom water could be derived. Therefore, the variance principle of Critical Producing Pressure Drop of horizontal well can be expressed quantitatively, and this paper also analyzes that it is influenced by the ratio of vertical permeability to horizontal permeability, the difference between water and gas density, the ratio of water viscosity to gas viscosity and height for bottom water coning. The results could provide guidelines for the determination of reasonable producing pressure drop and producing rate of horizontal well in gas reservoir with bottom water.


2013 ◽  
Vol 868 ◽  
pp. 657-663
Author(s):  
Wen Qi Zhao ◽  
Lian Yu ◽  
Lun Zhao ◽  
Li Chen ◽  
Song Chen

Banded gas reservoir with bottom water is a typical gas reservoir. Based on the development characteristics of formation, the further study on commingling production by transverse horizontal well is done, and also combined with seepage theory including the Green function, Duhamel method etc. the dimensionless definitions of relative parameter are given. Whats more, the derivation and formula of production can be achieved respectively under the constant pressure condition and constant production condition. Meanwhile, take commingling production with three banded gas layers for example. Whether the initial pseudo pressure for these layers are equal or not, in both of these cases, the variation curve of gas productivity under the constant pressure and constant rate conditions is described separately. And the law of variation of gas flow backward for some layer when the physical properties of these layers are significantly different.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Haidong Wang ◽  
Yikun Liu

The horizontal well completion with stinger is usually used to control the bottom water cone. Although the pressure profile and the inflow profile along the horizontal wellbore can be divided into two parts by the stinger, these profiles have not really flattened. In order to flatten the pressure distribution and inflow distribution further, it proposes a new technology. This new horizontal well has multiple artificial bottom holes (MABH) along the wellbore and it has application potential. In order to verify the effectiveness of MABH technology, a model of horizontal well completion with MABH was established, and the production performance of different water cone control technologies was analyzed: conventional horizontal well, stinger completion horizontal well, and MABH completion horizontal well. The results show that the MABH technology has more advantages than the stinger technology. The uniformity of pressure distribution of the 6-MABH horizontal well is 55% higher than that of the horizontal well with string technology, and the uniformity of inflow distribution is increased by 65.25%. At the same time, although the operation of MABH technology is very simple, it should follow a rule of MABH installation: the position of the first MABH should be set at 242.5 m from the heel hole of the horizontal wellbore, and the other interval is 92.4 m.


Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Yue Peng ◽  
Tao Li ◽  
Yuxue Zhang ◽  
Yongjie Han ◽  
Dan Wu ◽  
...  

Abstract Multifractured horizontal wells are widely used in the development of tight gas reservoirs to improve the gas production and the ultimate reservoir recovery. Based on the heterogeneity characteristics of the tight gas reservoir, the homogeneous scheme and four typical heterogeneous schemes were established to simulate the production of a multifractured horizontal well. The seepage characteristics and production performance of different schemes were compared and analyzed in detail by the analysis of streamline distribution, pressure distribution, and production data. In addition, the effects of reservoir permeability level, length of horizontal well, and fracture half-length on the gas reservoir recovery were discussed. Results show that the reservoir permeability of the unfractured areas, which are located at both ends of the multifractured horizontal well, determines the seepage ability of the reservoir matrix, showing a significant impact on the long-term gas production. High reservoir permeability level, long horizontal well length, and long fracture half-length can mitigate the negative influence of heterogeneity on the gas production. Our research can provide some guidance for the layout of multifractured horizontal wells and fracturing design in heterogeneous tight gas reservoirs.


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