scholarly journals Ball sealer tracking and seating of temporary plugging fracturing technology in the perforated casing of a horizontal well

2021 ◽  
pp. 014459872110204
Author(s):  
Wan Cheng ◽  
Chunhua Lu ◽  
Guanxiong Feng ◽  
Bo Xiao
Keyword(s):  
Critical Parameter ◽  
Fluid Velocity ◽  
Stable State ◽  
Horizontal Wells ◽  
Terminal Velocity ◽  
Injection Rate ◽  
Fracturing Fluid ◽  
Perforation Hole ◽  
Horizontal Wellbore ◽  
Tight Reservoirs

Multistaged temporary plugging fracturing in horizontal wells is an emerging technology to promote uniform fracture propagation in tight reservoirs by injecting ball sealers to plug higher-flux perforations. The seating mechanism and transportation of ball sealers remain poorly understood. In this paper, the sensitivities of the ball sealer density, casing injection rate and perforation angle to the seating behaviors are studied. In a vertical wellbore section, a ball sealer accelerates very fast at the beginning of the dropping and reaches a stable state within a few seconds. The terminal velocity of a non-buoyant ball is greater than the fluid velocity, while the terminal velocity of a buoyant ball is less than the fluid velocity. In the horizontal wellbore section, the terminal velocity of a non-buoyant or buoyant ball is less than the fracturing fluid flowing velocity. The ball sealer density is a more critical parameter than the casing injection rate when a ball sealer diverts to a perforation hole. The casing injection rate is a more critical parameter than the ball sealer density when a ball sealer seats on a perforation hole. A buoyant ball sealer associated with a high injection rate of fracturing fluid is highly recommended to improve the seating efficiency.

Experimental Study on Diverter Transport Through Perforations in Multicluster Fracturing of Horizontal Well

SPE Journal ◽  
2022 ◽  
pp. 1-15
Author(s):  
Lishan Yuan ◽  
Fujian Zhou ◽  
Minghui Li ◽  
Xuda Yang ◽  
Jiaqi Cheng ◽  
...  
Keyword(s):  
Large Scale ◽  
Horizontal Well ◽  
High Pressures ◽  
Flow Distribution ◽  
Experimental System ◽  
Injection Rate ◽  
Fluid Viscosity ◽  
Horizontal Wellbore ◽  
Tight Reservoirs ◽  
Large Flow

Summary Temporary plugging and diverting fracturing of the horizontal well is the primary option to promote production for tight reservoirs. Successful entry of diverters into the perforation is the basis and prerequisite for effective plugging. However, the transport behavior of the diverter during multicluster fracturing remains unclear. In this paper, we build a large-scale diverter transport experimental system, capable of conducting experiments with large flow rates and high pressures. The concerned factors include the injection rate, perforation flow ratio (PFRO), fluid viscosity, and perforation angle. The results show that the diverter transport effect is significantly different because of different flow distribution among perforations. Also, the diverter can enter the perforation only when the flow rate of the perforation reaches a certain value. In addition, the minimum critical PFRO has an “oblique L-shaped” relationship with the injection rate. Although it is difficult for the diverter to enter the perforation on the high side of the horizontal wellbore, increasing the viscosity of the carrying fluid or using a multidensity mixed diverter can effectively solve this problem. Furthermore, the field case shows that the experimentally obtained diverter transport pattern can be applied to the field to predict the location of the diverter and improve the temporary plugging effect. The findings of this work lay a theoretical foundation for subsequent temporary plugging and diverting fracturing control.

WELL TESTING HORIZONTALGAS-CONDENSATE WELLS

2017 ◽  
pp. 56-61
Author(s):  
M. L. Karnaukhov ◽  
O. N. Pavelyeva
Keyword(s):  
Comparative Analysis ◽  
Skin Effect ◽  
Horizontal Wells ◽  
Gas Condensate ◽  
Low Permeability ◽  
Well Testing ◽  
Flow Capacity ◽  
Formation Zone ◽  
Horizontal Wellbore

The well testing of gas-condensate horizontal wells are discussed in the article and the comparative analysis of borehole flow capacity, depending on the mode of it’s operation is presented. Extra attention is focused on the issue of timely identification of the reasons for the reduction of fluid withdrawal from the reservoir. The presence of high skin effect is proved, which confirms the existence of low-permeability of bottomhole formation zone related to condensation in the immediate area of the horizontal wellbore.

scholarly journals Concentration and velocity statistics of inertial particles in upward and downward pipe flow

2017 ◽  
Vol 822 ◽  
pp. 640-663 ◽  
Author(s):  
J. L. G. Oliveira ◽  
C. W. M. van der Geld ◽  
J. G. M. Kuerten
Keyword(s):  
Liquid Velocity ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Stokes Number ◽  
Terminal Velocity ◽  
Point Particle ◽  
Inertial Particles ◽  
Carrier Fluid ◽  
Velocity Statistics ◽  
The Difference

Three-dimensional particle tracking velocimetry is applied to particle-laden turbulent pipe flows at a Reynolds number of 10 300, based on the bulk velocity and the pipe diameter, for developed fluid flow and not fully developed flow of inertial particles, which favours assessment of the radial migration of the inertial particles. Inertial particles with Stokes number ranging from 0.35 to 1.11, based on the particle relaxation time and the radial-dependent Kolmogorov time scale, and a ratio of the root-mean-square fluid velocity to the terminal velocity of order 1 have been used. Core peaking of the concentration of inertial particles in up-flow and wall peaking in down-flow have been found. The difference in mean particle and Eulerian mean liquid velocity is found to decrease to approximately zero near the wall in both flow directions. Although the carrier fluid has all of the characteristics of the corresponding turbulent single-phase flow, the Reynolds stress of the inertial particles is different near the wall in up-flow. These findings are explained from the preferential location of the inertial particles with the aid of direct numerical simulations with the point-particle approach.

Chemical Plug for Zone Isolation in Horizontal Wells

1999 ◽  
Vol 121 (1) ◽  
pp. 40-44
Author(s):  
D. D. Mamora ◽  
N. F. Saavedra ◽  
D. B. Burnett ◽  
F. M. Platt
Keyword(s):  
Laboratory Study ◽  
Horizontal Wells ◽  
Full Scale ◽  
Horizontal Wellbore

A laboratory study has been conducted on the use of chemical plugs, instead of conventional mechanical packers, to isolate water and gas-producing zones in horizontal wells. Results of experiments using horizontal wellbore models, consisting of PVC pipes internally lined with sand, indicate that slumping of the chemical plug could be avoided if the plug were spotted in a viscous brine pill. Of the three chemicals tested, a monomer, a polyacrylamide, and a plastic, only the plastic plug had a sufficiently high holding pressure. Research is being continued using a full-scale horizontal wellbore model.

scholarly journals Study on the Interference Law of Staged Fracturing Crack Propagation in Horizontal Wells of Tight Reservoirs

ACS Omega ◽  
2020 ◽  
Vol 5 (18) ◽  
pp. 10327-10338
Author(s):  
Shaohua Gai ◽  
Zhihong Nie ◽  
Xinbin Yi ◽  
Yushi Zou ◽  
Zhaopeng Zhang
Keyword(s):  
Crack Propagation ◽  
Horizontal Wells ◽  
Tight Reservoirs

scholarly journals The Effect of Fracturing Fluid Saturation on Natural Gas Flow Behavior in Tight Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5278
Author(s):  
Mianmo Meng ◽  
Yinghao Shen ◽  
Hongkui Ge ◽  
Xiaosong Xu ◽  
Yang Wu
Keyword(s):  
Gas Flow ◽  
Water Saturation ◽  
Flow Behavior ◽  
Tight Gas ◽  
Fracturing Fluid ◽  
Taiyuan Formation ◽  
Irreducible Water Saturation ◽  
Tight Reservoirs ◽  
The One ◽  
Median Pore

Hydraulic fracturing becomes an essential method to develop tight gas. Under high injection pressure, fracturing fluid entering into the formation will reduce the flow channel. To investigate the influence of water saturation on gas flow behavior, this study conducted the gas relative permeability with water saturation and the flow rate with the pressure gradient at different water saturations. As the two dominant tight gas-bearing intervals, the Upper Paleozoic Taiyuan and Shihezi Formations deposited in Ordos Basin were selected because they are the target layers for holding vast tight gas. Median pore radius in the Taiyuan Formation is higher than the one in the Shihezi Formation, while the most probable seepage pore radius in the Taiyuan Formation is lower than the one in the Shihezi Formation. The average irreducible water saturation is 54.4% in the Taiyuan Formation and 61.6% in the Shihezi Formation, which indicates that the Taiyuan Formation has more movable water. The average critical gas saturation is 80.4% and 69.9% in these two formations, respectively, which indicates that the Shihezi Formation has more movable gas. Both critical gas saturation and irreducible water saturation have a negative relationship with porosity as well as permeability. At the same water saturation, the threshold gradient pressure of the Taiyuan Formation is higher than the one in the Shihezi Formation, which means that water saturation has a great influence on the Taiyuan Formation. Overall, compared with the Shihezi Formation, the Taiyuan Formation has a higher median pore size and movable water saturation, but water saturation has more influence on its gas flow capacity. Our research is conducive to understanding the effect of fracturing fluid filtration on the production of natural gas from tight reservoirs.

scholarly journals Study on Well Selection Method for Refracturing Horizontal Wells in Tight Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4202
Author(s):  
Qihong Feng ◽  
Jiawei Ren ◽  
Xianmin Zhang ◽  
Xianjun Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
Engineering Properties ◽  
Tight Oil ◽  
Well Test ◽  
Tree Model ◽  
Factors Affecting ◽  
Comprehensive Index ◽  
Tight Reservoirs ◽  
Potential Evaluation ◽  
Selection Of

Refracturing technology is one of the key technologies to recover the productivity of horizontal wells in tight oil reservoirs, and the selection of best candidate wells from target blocks is the basis of this technology. Based on the refracturing production database, this paper analyzes the direct relationship between geological data, initial fracturing completion data, and dynamic production data, and the stimulation effect of refracturing. Considering the interaction among multiple factors, the factors affecting the stimulation effect of refracturing are classified and integrated, and a comprehensive index including geology, engineering, and production is constructed, making this index meaningful both for physical and engineering properties. The XGBoost decision tree model is established to analyze the weight of influence for the comprehensive index of geology, engineering, and production in predicting the stimulation effect of refracturing. A comprehensive decision index of refracturing well selection is formed by combining the above three for performing a fast selection of horizontal candidate wells for fracturing. Taking a horizontal well test area in Songliao Basin as an example, the target wells of refracturing are selected by this method, and field operation is carried out, and a good stimulation effect is achieved. The results show that the comprehensive decision-making index constructed by this method is reliable and has certain guiding significance for well selection and stimulation potential evaluation of tight oil reservoir.

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