scholarly journals Development of water production type curves for horizontal wells in coalbed methane reservoirs

2007 ◽  
Author(s):  
Praveen Kumar Burka Narayana
2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Cheng-yong Li ◽  
Jun Zhou ◽  
Xiang-yi Yi ◽  
Yi Luo ◽  
Ping-zhi Gong

The bottom-hole pressure response which can reflect the gas flow characteristics is important to study. A mathematical model for description of gas from porous coalbed methane (CBM) reservoirs with complex boundary conditions flowing into horizontal wells has been developed. Meanwhile, basic solution of boundary elements has been acquired by combination of Lord Kelvin point source solution, the integral of Bessel function, and Poisson superimpose formula for CBM horizontal wells with complex boundary conditions. Using this model, type curves of dimensionless pressure and pressure derivative are obtained, and flow characteristics of horizontal wells in complex boundary reservoirs and relevant factors are accordingly analyzed.


2008 ◽  
Vol 11 (02) ◽  
pp. 311-325 ◽  
Author(s):  
Christopher R. Clarkson ◽  
Colin L. Jordan ◽  
Roger R. Gierhart ◽  
John P. Seidle

Summary Recent advances in production data analysis (PDA) techniques have greatly assisted engineers in extracting meaningful reservoir and stimulation information from well-production and flowing-pressure data. Application of these techniques to coalbed-methane (CBM) reservoirs requires the unique coal storage and transport properties to be accounted for. In recent work, the authors [ex. Clarkson et al. (2007a) and Jordan et al. (2006)] and others [ex. Gerami et al. (2007)] have demonstrated how new techniques such as the flowing material balance (FMB) and production type curves may be adapted to account for CBM storage mechanisms (i.e., adsorption), but, to date, the focus has been on relatively simple CBM reservoir behavior such as single-phase (gas) reservoirs with static effective permeability. The major contribution of the current work is the adaptation of modern PDA techniques (by use of modified material balance time/pseudotime and pseudopressure definitions) to analyze producing wells completed in CBM reservoirs exhibiting several possible flow characteristics: single-phase flow of gas in dry CBM reservoirs, single-phase flow of water (in undersaturated reservoirs), and two-phase (gas and water) flow (in saturated reservoirs). The latter reservoir type commonly exhibits effective permeability changes during depletion (because of relative and/or absolute permeability changes) and changing gas composition caused by relative adsorption effects, both of which have been accounted for in the current work. Specifically, the FMB technique is modified to include several complex CBM reservoir characteristics, and production type curves are applied to some scenarios. Although dry-CBM-well analysis was covered previously [ex. Clarkson et al. (2007a)], we will also discuss FMB development in these reservoirs for completeness. Several synthetic and field examples are given to demonstrate how FMB, type-curve analysis, and analytical simulation can be used in parallel to provide a particularly useful data-analysis toolset and workflow. These techniques were used successfully to extract quantitative reservoir information from single- and two-phase CBM-simulated and field-production pressure data. The PDA techniques developed for two-phase CBM require further evaluation, however.


Author(s):  
P. Noverri

Delta Mahakam is a giant hydrocarbon block which is comprised two oil fields and five gas fields. The giant block has been considered mature after production for more than 40 years. More than 2,000 wells have been drilled to optimize hydrocarbon recovery. From those wells, a huge amount of production data is available and documented in a well-structured manner. Gaining insight from this data is highly beneficial to understand fields behavior and their characteristics. The fields production characterization is analyzed with Production Type-Curve method. In this case, type curves were generated from production data ratio such as CGR, WGR and GOR to field recovery factor. Type curve is considered as a simple approach to find patterns and capture a helicopter view from a huge volume of production data. Utilization of business intelligence enables efficient data gathering from different data sources, data preparation and data visualization through dashboards. Each dashboard provides a different perspective which consists of field view, zone view, sector view and POD view. Dashboards allow users to perform comprehensive analysis in describing production behavior. Production type-curve analysis through dashboards show that fields in the Mahakam Delta can be grouped based on their production behavior and effectively provide global field understanding Discovery of production key information from proposed methods can be used as reference for prospective and existing fields development in the Mahakam Delta. This paper demonstrates an example of production type-curve as a simple yet efficient method in characterizing field production behaviors which is realized by a Business Intelligent application


SPE Journal ◽  
2020 ◽  
pp. 1-15
Author(s):  
Gang Li ◽  
Lifeng Chen ◽  
Meilong Fu ◽  
Lei Wang ◽  
Yadong Chen ◽  
...  

Summary Horizontal wells that are completed with slotted liners often suffer from a severe water-production problem, which is detrimental to oil recovery. It is because the annulus between the slotted liners and wellbore cannot be fully filled with common hydrogels with poor thixotropy, which determines the ultimate hydrogel filling shape in the annulus. This paper presents a novel hydrogel with high thixotropy to effectively control water production in horizontal wells. This study is aimed at evaluating the thixotropic performance, gelation time, plugging performance, and degradation performance. The thixotropic performance of the new hydrogel was also investigated by measuring its rheological properties and examining its microstructures. It was found that the new hydrogel thickened rapidly after shearing. Its thixotropic recovery coefficient was 1.747, which was much higher than those of traditional hydrogels. The gelation time can be controlled in the range of 2 to 8 hours by properly adjusting the concentrations of the framework material, crosslinker, and initiator. The hydrogel could be customized for mature oil reservoirs, at which it was stable for more than 90 days. A series of laboratory physical modeling tests showed that the breakthrough pressure gradient and the plugging ratio of the hydrogel in sandpacks were higher than 9.5 MPa/m and 99%, respectively. At the same time, it was found that the hydrogel has good degradation properties; the viscosity of the hydrogel breaking solution was 4.22 mPa·s. Freeze-etching scanning-electron-microscopy examinations indicated that the hydrogel had a uniform grid structure, which can be broken easily by shear and restored quickly. This led to the remarkable thixotropic performance. The formation of a metastable structure caused by the electrostatic interaction and coordination effect was considered to be the primary reason for the high thixotropy. The successful development of the new thixotropic hydrogel not only helps to control water production from the horizontal wells, but also furthers the thixotropic theory of hydrogel. This study also provides technical guidelines for further increasing the thixotropies of drilling fluids, fracturing fluids, and other enhanced-oil-recovery polymers that are commonly used in the petroleum industry.


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