Analytical Design of Water-Free Production in Horizontal Wells Using Hodograph Method / Zastosowanie metody hodografu do określenia krytycznego wydatku poziomych otworów produkcyjnych

2013 ◽  
Vol 58 (2) ◽  
pp. 287-300
Author(s):  
Wenting Qin ◽  
Andrew K. Wojtanowicz ◽  
Christopher D. White
Keyword(s):  
Analytical Model ◽  
Contact Area ◽  
Horizontal Well ◽  
Productivity Loss ◽  
Critical Rate ◽  
Hodograph Method ◽  
Well Production ◽  
Water Breakthrough ◽  
Large Contact Area ◽  
Good Productivity

Horizontal well has been widely used as a solution for oil reservoir with underlain strong water drive. The advantage of horizontal well over vertical well is to increase the reservoir contact and thereby enhance well productivity. Because of that, horizontal well can provide a very low pressure drawdown to avoid the water coning and still sustain a good productivity. However, the advantage of the large contact area with reservoir will soon become the disadvantage when the water breakthrough into the horizontal well. The water cut will increase rapidly due to the large contact area with reservoir and it may cause the productivity loss of the whole well. Therefore, keeping the horizontal well production rate under critical rate is crucial. However, existing models of critical rate either oversimplify or misrepresent the nature of the WOC interface, resulting in misestimating the critical rate. In this paper, a new analytical model of critical rate is presented to provide accurate calculations on this subject for project design and performance predictions. Unlike the conventional approach, in which the flow restriction due to the water crest shape has been neglected; including the distortions of oil-zone flow caused by the rising water crest, the new analytical model gives an accurate simultaneous determination of the critical rate, water crest shape and the pressure distribution in the oil zone by using hodograph method combined with conformal mapping. The accuracy of this model was confirmed by numerical simulations. The results show that neglecting the presence of water crest leads to up to 50 percent overestimation of critical rates.

Research and Application on Homogeneous Acidification to Enhance Producing Degree of Horizontal Wells

2014 ◽  
Vol 675-677 ◽  
pp. 1526-1529
Author(s):  
Hua Long
Keyword(s):  
Contact Area ◽  
Horizontal Well ◽  
Field Experiments ◽  
Horizontal Wells ◽  
Long Time ◽  
Large Contact Area

The homogeneous acidification technology for Horizontal well is developed to solve the problem of serious pollution in near wellbore area owing to long-time mud soak and large contact area of injected fluid. It not only reduces cost, but also improves acidification efficiency and controllability of horizontal wells. Through field experiments, the technology has got great achievements on eliminating well pollution and increasing productivity.

Adhesion of Wax Droplets to Porous Substrates

2012 ◽  
Author(s):  
Shima Dadvar ◽  
Sanjeev Chandra ◽  
Nasser Ashgriz ◽  
Stephan Drappel
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Impact Velocity ◽  
Analytical Model ◽  
Contact Area ◽  
Initial Temperature ◽  
Simple Analytical Model ◽  
Porous Polyethylene ◽  
Porous Surfaces ◽  
Strength Of Adhesion

The adhesion of solid wax ink droplets to porous polyethylene and Teflon substrates was studied experimentally. Wax droplets with a diameter of 3 mm and an initial temperature of 110°C were dropped onto test surfaces from heights varying from 20–50 mm. The Teflon surfaces had holes drilled in them to create idealized porous surfaces while the porous polyethylene sheets had mean pore sizes of either 35 or 70 μm. The force required to remove the wax splats from the substrates was measured by a pull test. The detachment force increased with droplet impact velocity. A simple analytical model is proposed to predict the force attaching the wax splat to the surface: it has an adhesive component, calculated by multiplying the contact area between the splat and substrate by the strength of adhesion; and a cohesive component, calculated by multiplying the area of the pores into which wax penetrates by the ultimate tensile strength of wax. Predictions from the model agreed reasonably well with measurements.

scholarly journals Prediction of water breakthrough time in horizontal Wells in edge water condensate gas reservoirs

2020 ◽  
Vol 213 ◽  
pp. 02009
Author(s):  
Quan Hua Huang ◽  
Xing Yu Lin
Keyword(s):  
Horizontal Well ◽  
Negative Impact ◽  
Horizontal Wells ◽  
Breakthrough Time ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Water Breakthrough ◽  
Calculation Results ◽  
Seepage Model ◽  
Reasonable Prediction

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.

Understanding receptor-mediated endocytosis of elastic nanoparticles through coarse grained molecular dynamic simulation

2018 ◽  
Vol 20 (24) ◽  
pp. 16372-16385 ◽  
Author(s):  
Zhiqiang Shen ◽  
Huilin Ye ◽  
Ying Li
Keyword(s):  
Molecular Dynamic Simulation ◽  
Molecular Dynamic ◽  
Dynamic Simulation ◽  
Contact Area ◽  
Late Stage ◽  
Early Stage ◽  
Coarse Grained ◽  
Large Energy ◽  
Receptor Mediated Endocytosis ◽  
Large Contact Area

The membrane wrapping of the soft nanoparticle (NP) is faster than that of the stiff one at the early stage, due to the NP deformation induced large contact area between the NP and membrane. However, because of the large energy penalties induced by the NP deformation, the membrane wrapping speed of soft NPs slows down during the late stage.

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

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
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.

scholarly journals The Key Factors That Determine the Economically Viable, Horizontal Hydrofractured Gas Wells in Mudrocks

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2348 ◽  
Author(s):  
Syed Haider ◽  
Wardana Saputra ◽  
Tadeusz Patzek
Keyword(s):  
Gas Flow ◽  
Horizontal Well ◽  
Source Term ◽  
Organic Matrix ◽  
Fracture Network ◽  
Gas Production ◽  
Fracture Permeability ◽  
Gas Wells ◽  
Stimulated Reservoir Volume ◽  
Well Production

We assemble a multiscale physical model of gas production in a mudrock (shale). We then tested our model on 45 horizontal gas wells in the Barnett with 12–15 years on production. When properly used, our model may enable shale companies to gain operational insights into how to complete a particular well in a particular shale. Macrofractures, microfractures, and nanopores form a multiscale system that controls gas flow in mudrocks. Near a horizontal well, hydraulic fracturing creates fractures at many scales and increases permeability of the source rock. We model the physical properties of the fracture network embedded in the Stimulated Reservoir Volume (SRV) with a fractal of dimension D < 2 . This fracture network interacts with the poorly connected nanopores in the organic matrix that are the source of almost all produced gas. In the practically impermeable mudrock, the known volumes of fracturing water and proppant must create an equal volume of fractures at all scales. Therefore, the surface area and the number of macrofractures created after hydrofracturing are constrained by the volume of injected water and proppant. The coupling between the fracture network and the organic matrix controls gas production from a horizontal well. The fracture permeability, k f , and the microscale source term, s, affect this coupling, thus controlling the reservoir pressure decline and mass transfer from the nanopore network to the fractures. Particular values of k f and s are determined by numerically fitting well production data with an optimization algorithm. The relationship between k f and s is somewhat hyperbolic and defines the type of fracture system created after hydrofracturing. The extremes of this relationship create two end-members of the fracture systems. A small value of the ratio k f / s causes faster production decline because of the high microscale source term, s. The effective fracture permeability is lower, but gas flow through the matrix to fractures is efficient, thus nullifying the negative effect of the smaller k f . For the high values of k f / s , production decline is slower. In summary, the fracture network permeability at the macroscale and the microscale source term control production rate of shale wells. The best quality wells have good, but not too good, macroscale connectivity.

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