Establishment of the productivity prediction method of Class III gas hydrate developed by depressurization and horizontal well based on production performance and inflow relationship

The most advanced technique to evaluate different solutions proposed for a field development plan consists of building a numerical model to simulate the production performance of each alternative. Fields covering hundreds of square kilometres frequently require a large number of wells. There are studies and software concerning optimal planning of vertical wells for the development of a field. However, only few studies cover planning of a large number of horizontal wells seeking full population on a regular pattern. One of the criteria for horizontal well planning is selecting the well positions that have the best reservoir properties and certain standoffs from oil/water contact. The wells are then ranked according to their performances. Other criteria include the geometry and spacing of the wells. Placing hundreds of well individually according to these criteria is highly time consuming and can become impossible under time restraints. A method for planning a large number of horizontal wells in a regular pattern in a simulation model significantly reduces the time required for a reservoir production forecast using simulation software. The proposed method is implemented by a computer script and takes into account not only the aforementioned criteria, but also new well requirements concerning existing wells, development area boundaries, and reservoir geological structure features. Some of the conclusions drawn from a study on this method are (1) the new method saves a significant amount of working hours and avoids human errors, especially when many development scenarios need to be considered; (2) a large reservoir with hundreds of wells may have infinite possible solutions, and this approach has the aim of giving the most significant one; and (3) a horizontal well planning module would be a useful tool for commercial simulation software to ease engineers' tasks.

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Fatigue Life Prediction of Buckling String with Cracks in Horizontal Wells of Mining Engineering

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.577.127 ◽

2012 ◽

Vol 577 ◽

pp. 127-131 ◽

Cited By ~ 1

Author(s):

Peng Wang ◽

Tie Yan ◽

Xue Liang Bi ◽

Shi Hui Sun

Keyword(s):

Fatigue Life ◽

Prediction Model ◽

Life Prediction ◽

Horizontal Well ◽

Drill Pipe ◽

Prediction Method ◽

Drill String ◽

Fatigue Life Prediction ◽

Mining Engineering ◽

Life Prediction Model

Fatigue damage in the rotating drill pipe in the horizontal well of mining engineering is usually resulted from cyclic bending stresses caused by the rotation of the pipe especially when it is passing through curved sections or horizontal sections. This paper studies fatigue life prediction method of rotating drill pipe which is considering initial crack in horizontal well of mining engineering. Forman fatigue life prediction model which considering stress ratio is used to predict drill string fatigue life and the corresponding software has been written. The program can be used to calculate the stress of down hole assembly, can predict stress and alternating load in the process of rotating-on bottom. Therefore, establishing buckling string fatigue life prediction model with cracks can be a good reference to both operation and monitor of the drill pipe for mining engineering.

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Production Rate Analysis of Fractured Horizontal Well considering Multitransport Mechanisms in Shale Gas Reservoir

Geofluids ◽

10.1155/2018/3148298 ◽

2018 ◽

Vol 2018 ◽

pp. 1-17 ◽

Cited By ~ 1

Author(s):

Qi-guo Liu ◽

Wei-hong Wang ◽

Hua Liu ◽

Guangdong Zhang ◽

Long-xin Li ◽

...

Keyword(s):

Production Rate ◽

Shale Gas ◽

Horizontal Well ◽

Production Performance ◽

Natural Fractures ◽

Gas Reservoir ◽

Isothermal Adsorption ◽

Well Production ◽

Shale Gas Reservoir ◽

Fractured Horizontal Well

Shale gas reservoir has been aggressively exploited around the world, which has complex pore structure with multiple transport mechanisms according to the reservoir characteristics. In this paper, a new comprehensive mathematical model is established to analyze the production performance of multiple fractured horizontal well (MFHW) in box-shaped shale gas reservoir considering multiscaled flow mechanisms (ad/desorption and Fick diffusion). In the model, the adsorbed gas is assumed not directly diffused into the natural macrofractures but into the macropores of matrix first and then flows into the natural fractures. The ad/desorption phenomenon of shale gas on the matrix particles is described by a combination of the Langmuir’s isothermal adsorption equation, continuity equation, gas state equation, and the motion equation in matrix system. On the basis of the Green’s function theory, the point source solution is derived under the assumption that gas flow from macropores into natural fractures follows transient interporosity and absorbed gas diffused into macropores from nanopores follows unsteady-state diffusion. The production rate expression of a MFHW producing at constant bottomhole pressure is obtained by using Duhamel’s principle. Moreover, the curves of well production rate and cumulative production vs. time are plotted by Stehfest numerical inversion algorithm and also the effects of influential factors on well production performance are analyzed. The results derived in this paper have significance to the guidance of shale gas reservoir development.

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The Rule of Carrying Cuttings in Horizontal Well Drilling of Marine Natural Gas Hydrate

Energies ◽

10.3390/en13051129 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1129 ◽

Cited By ~ 2

Author(s):

Na Wei ◽

Yang Liu ◽

Zhenjun Cui ◽

Lin Jiang ◽

Wantong Sun ◽

...

Keyword(s):

Particle Size ◽

Flow Velocity ◽

Gas Hydrate ◽

Horizontal Well ◽

Drilling Fluid ◽

Test Method ◽

Critical Flow ◽

Fluid Density ◽

Critical Flow Velocity ◽

Orthogonal Test Method

Horizontal well drilling is a highly effective way to develop marine gas hydrate. During the drilling of horizontal wells in the marine gas hydrate layer, hydrate particles and cutting particles will migrate with the drilling fluid in the horizontal annulus. The gravity of cuttings is easy to deposit in the horizontal section, leading to the accumulation of cuttings. Then, a cuttings bed will be formed, which is not beneficial to bring up cuttings and results in the decrease of wellbore purification ability. Then the extended capability of the horizontal well will be restricted and the friction torque of the drilling tool will increase, which may cause blockage of the wellbore in severe cases. Therefore, this paper establishes geometric models of different hole enlargement ways: right-angle expansion, 45-degree angle expansion, and arc expanding. The critical velocity of carrying rock plates are obtained by EDEM and FLUENT coupling simulation in different hydrate abundance, different hydrate-cuttings particle sizes and different drilling fluid density. Then, the effects of hole enlargement way, particle size, hydrate abundance and drilling fluid density on rock carrying capacity are analyzed by utilizing an orthogonal test method. Simulation results show that: the critical flow velocity required for carrying cuttings increases with the increase of the particle size of the hydrate-cuttings particle when the hydrate abundance is constant. The critical flow velocity decreases with the increase of drilling fluid density, the critical flow velocity carrying cuttings decreases with the increase of hydrate abundance when the density of the drilling fluid is constant. Orthogonal test method was used to evaluate the influence of various factors on rock carrying capacity: hydrate-cuttings particle size > hole enlargement way > hydrate abundance > drilling fluid density. This study provides an early technical support for the construction parameter optimization and well safety control of horizontal well exploitation models in a marine natural gas hydrate reservoir.

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An Early-Time Model for Drawdown Testing of a Hydrate-Capped Gas Reservoir

SPE Reservoir Evaluation & Engineering ◽

10.2118/108971-pa ◽

2009 ◽

Vol 12 (04) ◽

pp. 595-609 ◽

Cited By ~ 6

Author(s):

Shahab Gerami ◽

Mehran Pooladi-Darvish

Keyword(s):

Gas Hydrate ◽

Gas Production ◽

Production Performance ◽

Gas Reservoir ◽

Unconventional Gas ◽

Free Gas ◽

Hydrate Decomposition ◽

Hydrate Reservoir ◽

Wellbore Pressure ◽

Hydrate Reservoirs

Summary Development of natural gas hydrates as an energy resource has gained significant interest during the past decade. Hydrate reservoirs may be found in different geologic settings including deep ocean sediments and arctic areas. Some reservoirs include a free-gas zone beneath the hydrate and such a situation is referred to as a hydrate-capped gas reservoir. Gas production from such a reservoir could result in pressure reduction in the hydrate cap and endothermic decomposition of hydrates. Well testing in conventional reservoirs is used for estimation of reservoir and near-wellbore properties. Drawdown testing in a hydrate-capped gas reservoir needs to account for the effect of gas from decomposing hydrates. This paper presents a 2D (r,z) mathematical model for a constant-rate drawdown test performed in a well completed in the free-gas zone of a hydrate-capped gas reservoir during the earlytime production. Using energy and material balance equations, the effect of endothermic hydrate decomposition appears as an increased compressibility in the resulting governing equation. The solution for the dimensionless wellbore pressure is derived using Laplace and finite Fourier cosine transforms. The solution to the analytical model was compared with a numerical hydrate reservoir simulator across some range of hydrate reservoir parameters. The use of this solution for determination of reservoir properties is demonstrated using a synthetic example. Furthermore, the solution may be used to quantify the contribution of hydrate decomposition on production performance. Introduction In recent years, demands for energy have stimulated the development of unconventional gas resources, which are available in enormous quantities around the world. Gas hydrate as an unconventional gas resource may be found in two geologic settings (Sloan 1991):on land in permafrost regions, andin the ocean sediments of continental margins. During the last decade, extensive efforts consisting of detection of the hydrate-bearing areas, drilling, logging, coring of the intervals, production pilot-testing, and mathematical modeling of hydrate reservoirs have been pursued to evaluate the potential of gas production from these gas-hydrate resources.

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Productivity-Prediction Model of Acid Fracturing Horizontal Well in Fracture-Cavity Reservoir

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.321-324.872 ◽

2013 ◽

Vol 321-324 ◽

pp. 872-876

Author(s):

Yang He ◽

Yong Ming Li ◽

Jin Zhou Zhao ◽

Ye Zhang ◽

Tao Lin ◽

...

Keyword(s):

Prediction Model ◽

Horizontal Well ◽

Material Balance ◽

Production Capacity ◽

Basic Principles ◽

Acid Fracturing ◽

Oil Storage ◽

Cavity System ◽

Seepage Theory ◽

Productivity Prediction

Due to the particularity of the fracture-cavity reservoir space, the seepage theory developed from homogeneous reservoir cant be applied to predict the productivity of fracture-cavity reservoir. This paper simplified the fracture-cavity system to an oil storage vessel, and based on the basic principles of material balance, established the productivity-prediction model which was suitable for the acid fracturing horizontal well in fracture-cavity reservoir. The results showed that the productivity of fracture-cavity system was high and steady. Meanwhile, the connected fracture-cavity system had a greater contribution to increasing production capacity than other factors.

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