Absolute open flow (AOF) potential evaluation for watered-out gas wells in water-drive gas reservoir

2021 ◽  
pp. 1-21
Author(s):  
Xiaohua Liu ◽  
Fankun Meng ◽  
Qian Li ◽  
Zhenhua Guo ◽  
Weijun Shen ◽  
...  
Keyword(s):  
Gas Wells ◽  
Gas Reservoir ◽  
Open Flow ◽  
Potential Evaluation

Non-Darcy Binomial Deliverability Equations for Partially Penetrating Vertical Gas Wells and Horizontal Gas Wells

2009 ◽  
Author(s):  
Tao Zhu ◽  
Jing Lu
Keyword(s):  
Bottom Water ◽  
Horizontal Wells ◽  
Vertical Wells ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Well ◽  
Increase Productivity ◽  
Flow Domain ◽  
Inflow Performance

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.

scholarly journals Shale gas well productivity potential evaluation based on data-driven methods: case study in the WY block

2022 ◽  
Author(s):  
Chaodong Tan ◽  
Hanwen Deng ◽  
Wenrong Song ◽  
Huizhao Niu ◽  
Chunqiu Wang
Keyword(s):  
Shale Gas ◽  
Production Optimization ◽  
Data Driven ◽  
Operating Parameters ◽  
Geological Condition ◽  
Gas Wells ◽  
Gas Well ◽  
Geological Conditions ◽  
Potential Evaluation ◽  
Productivity Potential

AbstractEvaluating the productivity potential of shale gas well before fracturing reformation is imperative due to the complex fracturing mechanism and high operation investment. However, conventional single-factor analysis method has been unable to meet the demand of productivity potential evaluation due to the numerous and intricate influencing factors. In this paper, a data-driven-based approach is proposed based on the data of 282 shale gas wells in WY block. LightGBM is used to conduct feature ranking, K-means is utilized to classify wells and evaluate gas productivity according to geological features and fracturing operating parameters, and production optimization is realized through random forest. The experimental results show that shale gas productivity potential is basically determined by geological condition for the total influence weights of geologic properties take the proportion of 0.64 and that of engineering attributes is 0.36. The difference between each category of well is more obvious when the cluster number of well is four. Meanwhile, those low production wells with good geological conditions but unreasonable fracturing schemes have the greatest optimization space. The model constructed in this paper can classify shale gas wells according to their productivity differences, help providing suggestions for engineers on productivity evaluation and the design of fracturing operating parameters of shale gas well.

Pressure Drop Characteristics and Reserves Calculation Method of Gas Reservoir of Multi-Layer Unconsolidated Sandstone

2012 ◽  
Vol 616-618 ◽  
pp. 864-869
Author(s):  
Pang Jin ◽  
Hong Liu ◽  
Xiao Lu Wang
Keyword(s):  
Pressure Drop ◽  
Formation Pressure ◽  
Accurate Calculation ◽  
Gas Wells ◽  
Gas Reservoir ◽  
Gas Field ◽  
Practical Result ◽  
Straight Line ◽  
Sand Control ◽  
Pressure Test

Taking Sebei gas field as an example, this paper sorts hydrostatic pressure test data over the years and summarizes the reasons that the formation pressure drop curve generates a straight line, up-warping and recurvation from the perspective of water invasion, perforation adding, layer adjusting, sand burying, and sand control as well as inter-layer interference and inter-well interference, with typical wells analyzed and explained. On this basis, two kinds of mass balance correction models which have taken the offset of the pressure drop curve into account are proposed to calculate the dynamic reserves of gas wells with different offset shapes of pressure drop curves. Practical result shows the simple concept and strong practicality of this method, which provides an effective method for the accurate calculation of dynamic reserves of such gas reservoir.

scholarly journals A productivity prediction method for condensate gas reservoir

2020 ◽  
Vol 213 ◽  
pp. 02001
Author(s):  
Quan Hua Huang ◽  
Hong Jun Ding ◽  
Xing Yu Lin
Keyword(s):  
Pressure Gradient ◽  
Stress Sensitivity ◽  
Water Production ◽  
Gas Wells ◽  
Gas Reservoir ◽  
Gas Well ◽  
Well Productivity ◽  
Inclined Angle ◽  
The Impact ◽  
Starting Pressure Gradient

At present, multiphase flow productivity calculation requires many parameters, and most of them only consider oil and gas two-phase flow, which is complicated and limited. Therefore, a reasonable productivity formula of condensate gas reservoir with producing water is needed. The three-zone model of condensate gas reservoirs is generally applied to the physical model for inferring productivity. On this basis, an improved model is established, which includes that different seepage characteristics are considered for different zones. Moreover, the effects of inclined angle and water production on gas wells are regarded as pseudo-skin factors and additional-skin factors. In addition, Zone I considers the effects of high-speed nonDarcy effect(HSND), starting pressure gradient, stress sensitivity, inclined angle and water production; Zone II is the same way excepting starting pressure gradient and stress sensitivity ; Zone III only considers the effects of inclined angle and water production. As a result, a productivity equation with multiple factors for condensate gas wells is established. Through analysing cases and influences in H gas reservoir X1 well, the HSND, starting pressure gradient, stress sensitivity and water production have a negative impact on gas well productivity, but the inclined angle is opposite. Founded that the starting pressure gradient impacts on productivity is less than the HSND because of the limited radius of Zone I; the impact of the HSND on productivity increases with the decreasing of bottom hole pressure; the impact of water production on gas well productivity is much higher. When the angle is over 60°, the effect of gas

scholarly journals Productivity Testing and Analysis of Low Permeability and Thick Layer of N Gas Field

2020 ◽  
Vol 213 ◽  
pp. 02002
Author(s):  
Quan Hua Huang ◽  
Xing Yu Lin ◽  
Zhi-xing Yang ◽  
Ke-feng Lu ◽  
Xian-kang Hu
Keyword(s):  
Steady State ◽  
Statistical Method ◽  
Thick Layer ◽  
Theory Model ◽  
Theoretical Formula ◽  
Low Permeability ◽  
Testing Time ◽  
Gas Wells ◽  
Gas Reservoir ◽  
Gas Field

For a better guidance of production, a combination of drill stem testing (DST), regional statistical method and pseudo steady-state seepage theory model was used to analyze the productivity of N gas reservoir in light of the complex geological features of the low-permeability thick-layer. Firstly, the DST method was used to test the N gas reservoir. And then the binomial pseudo-pressure method, binomial pressure square method and exponential method were used to interpret the test data of DST of this formation. Finally, the binomial pseudo-pressure interpretation method was used and the results showed that only the productivity of H3b layer was successfully tested of the four. The H3a, H4b and H5a layers are ultra-low pore and permeability gas reservoirs and the productivity of these layers can’t be explained by the available data due to the short testing time and a non-stationary state of testing pressure and quantity, resulting in the failure of the test. The productivity of the main layers were estimated and forecasted by the regional statistical method and the theoretical model of pseudo steady-state seepage, taking the arithmetic average value of the regional statistical method and the theoretical formula as the final value of absolute open flow rates(AOF). The final calculation results are as follows: the AOF of main gas layers H3a, H3b, H4b and H5a in N gas field is 31.30×104m3/d, 388.92×104m3/d, 20.82×104m3/d and 30.80×104m3/d, respectively. This method may sheds light on verifying and calculating the productivity of gas wells and determining the reasonable production allocation of gas wells.

scholarly journals The Researches on Reasonable Well Spacing of Gas Wells in Deep and low Permeability Gas Reservoirs

2018 ◽  
Vol 38 ◽  
pp. 01038
Author(s):  
Yu Bei Bei ◽  
Li Hui ◽  
Li Dong Lin
Keyword(s):  
Pressure Gradient ◽  
Low Permeability ◽  
Well Testing ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Field ◽  
Well Spacing ◽  
Start Up ◽  
Starting Pressure Gradient

This Gs64 gas reservoir is a condensate gas reservoir which is relatively integrated with low porosity and low permeability found in Dagang Oilfield in recent years. The condensate content is as high as 610g/m3. At present, there are few reports about the well spacing of similar gas reservoirs at home and abroad. Therefore, determining the reasonable well spacing of the gas reservoir is important for ensuring the optimal development effect and economic benefit of the gas field development. This paper discusses the reasonable well spacing of the deep and low permeability gas reservoir from the aspects of percolation mechanics, gas reservoir engineering and numerical simulation. considering there exist the start-up pressure gradient in percolation process of low permeability gas reservoir, this paper combined with productivity equation under starting pressure gradient, established the formula of gas well spacing with the formation pressure and start-up pressure gradient. The calculation formula of starting pressure gradient and well spacing of gas wells. Adopting various methods to calculate values of gas reservoir spacing are close to well testing' radius, so the calculation method is reliable, which is very important for the determination of reasonable well spacing in low permeability gas reservoirs.

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