scholarly journals Perforation Optimization of Intensive-Stage Fracturing in a Horizontal Well Using a Coupled 3D-DDM Fracture Model

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2393
Author(s):  
Wan Cheng ◽  
Chunhua Lu ◽  
Bo Xiao

Intensive-stage fracturing in horizontal wells is a potentially new technology for reservoir stimulations of deep shale oil and gas. Due to a strong stress interaction among the dense fractures, the fracture geometry and stress field are very complicated, which are the bottlenecks of this technology. Aiming at simulating the intensive-stage fracturing, a coupled three-dimensional (3D) fracture model of multiple-fracture simultaneous propagation is proposed. The dynamic behavior of the fracture propagation and stress field was analyzed using this model. The perforation parameters were optimized for improving the fracture geometry equilibrium. The results showed that the exterior fractures of the multiple fractures penetrated by the horizontal well become the main fractures, while the interior fractures are drastically restrained. The exterior fracture widths increased with increasing injection time, while the interior fracture widths decreased with increasing injection time. An extruded region was created among the multiple fractures, which restrained the propagation of the interior fractures. Only increasing the perforation cluster number did not improve the fracture geometry equilibrium in the intensive-stage fracturing. To improve the fracture geometry equilibrium, we suggest designing more perforation numbers in each perforation cluster and ensuring that both the perforation number and diameter in the interior perforation cluster are greater than those of the exterior ones.

Geophysics ◽  
2018 ◽  
Vol 83 (3) ◽  
pp. MR153-MR166
Author(s):  
Yao Yao ◽  
Kaimin Wang ◽  
Tao Zeng ◽  
Leon M. Keer

Hydraulic fracture technology has been widely applied to improve unconventional oil and gas production. The prevailing numerical analysis for hydraulic fracture technology is mainly based on the assumption of a homogeneous reservoir. However, unconventional reservoirs usually have complicated geologic conditions and the hypothesis of the homogeneous reservoir can strongly affect the accuracy of fracture simulation. To better understand the influence of heterogeneity to hydraulic fracture development, the effects of inclusions and heterogeneous stress fields are investigated by using the extended finite-element method. The heterogeneous stress field with fracture processing is developed, and the corresponding interaction between fracture and inclusion is investigated. The effects of different inclusions positions, opening and rotation angles, fractures lengths, and injected fluid viscosities to the hydraulic fracture development are studied based on the developed numerical model. Compared with the homogeneous stress field, numerical analysis indicates that the heterogeneous stress field could affect fracture behaviors and change the fracture energy distribution. In addition, the effects of inclusion can be restricted to some extent with higher injected fluid viscosity. The “stress shadow” effect with multiple fractures can weaken the influence of inclusions with properly designed perforation locations, which may be applied to optimize the hydraulic fracture development.


2021 ◽  
Author(s):  
Youngbin Shan ◽  
Hongjun Lu ◽  
Qingbo Jiang ◽  
Zhijun Li ◽  
Jianpeng Xue ◽  
...  

Abstract The objective of the paper is to introduce a new technology which secures long horizontal casing deployment by a reliable casing flotation technology. It is common nowadays to drill a slim hole and extends to long horizontal extension to pay zones in condensate and shale oil and gas reservoir. To assure a successful casing deployment into the horizontal section, a flotation collar is often installed to float the casing in horizontal to mitigate the friction and Torque & Drag. However, slim casing may encounter difficulty in circulation and subsequent cementing even after the collar is broken. A new proprietary technique proposed in this paper solved above contingencies and secured 100% success in casing deployment, This technique secures smoothly circulation and cementing by flotating air in horizontal casing interval and purging air out of hole to overcome Spring Effect before circulation and cementing. Often, the flotation collar is made of proprietary material that can break or explodes under certain hydraulic pressure. After breaking, the whole collar becomes a portion of casing with exact the same ID of casing or a very small difference that does not have any negative effect to subsequent Plug & Perf, frac, tools running through and fluid movement. For long horizontal length of small open hole and casing sizes, casing deployment may be difficult if the Torque & Drag and friction through the low sides can not be mitigated. This paper proposes a new technique to fill air full of horizontal interval along inside the casing and ensure a sufficient of air purging to overcome Spring Effect before circulation and cementing. So far twelve (12) wells have been successfully completed including Asian longest horizontal gas well with 7,388.18m measured depth and 4,118.18m horizontal length. All jobs are 100% successful and there is no difficulty in mud circulation and cementing. Even for the longest 4,118.18m horizontal length casing deployment, the hook weight on surface when casing reached the total depth still remained 20 MT. Before this technique was applied, operators were unable to deploy 4 ½" casing through a 6" bit hole beyond 1500m horizontal length. Most often the hook weight at surface were zero when casing extended to almost 1500m in horizontal length. This new technique brings a great value to operators to complete longer horizontal well to yield more production with less investment.


2020 ◽  
Author(s):  
Hongfeng Sheng ◽  
Weixing Xu ◽  
Bin Xu ◽  
Hongpu Song ◽  
Di Lu ◽  
...  

UNSTRUCTURED The retrospective study of Taylor's three-dimensional external fixator for the treatment of tibiofibular fractures provides a theoretical basis for the application of this technology. The paper collected 28 patients with tibiofibular fractures from the Department of Orthopaedics in our hospital from March 2015 to June 2018. After the treatment, the follow-up evaluation of Taylor's three-dimensional external fixator for the treatment of tibiofibular fractures and concurrency the incidence of the disease, as well as the efficacy and occurrence of the internal fixation of the treatment of tibial fractures in our hospital. The results showed that Taylor's three-dimensional external fixator was superior to orthopaedics in the treatment of tibiofibular fractures in terms of efficacy and complications. To this end, the thesis research can be concluded as follows: Taylor three-dimensional external fixation in the treatment of tibiofibular fractures is more effective, and the incidence of occurrence is low, is a new technology for the treatment of tibiofibular fractures, it is worthy of clinical promotion.


e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 346-354
Author(s):  
Guoquan Qi ◽  
Hongxia Yan ◽  
Dongtao Qi ◽  
Houbu Li ◽  
Lushi Kong ◽  
...  

Abstract The chapter deals with the performance evaluation of the polyethylene of raised temperature resistance (PE-RT) and polyethylene (PE) using autoclave test under sour oil and gas medium conditions. The analyses of performance changes showed that PE-RT has good media resistance at 60°C. As the temperature increases, its mechanical properties decrease, accompanied by an increase in weight. Comparative analyses showed that no matter what temperature conditions are, PE-RT media resistance is better than PE80. The better media resistance of PE-RT depends on its higher degree of branching. Short branches are distributed between the crystals to form a connection between the crystals, thereby improving its heat resistance and stress under high-temperature conditions. PE-RT forms an excellent three-dimensional network structure through copolymerization, ensuring that it has better media resistance than PE80. However, the mechanical performance will be attenuated due to the high service temperature.


2021 ◽  
Vol 11 (8) ◽  
pp. 3635
Author(s):  
Ioannis Liritzis ◽  
Pantelis Volonakis ◽  
Spyros Vosinakis

In the field of cultural heritage, three-dimensional (3D) reconstruction of monuments is a usual activity for many professionals. The aim in this paper focuses on the new technology educational application combining science, history, and archaeology. Being involved in almost all stages of implementation steps and assessing the level of participation, university students use tools of computer gaming platform and participate in ways of planning the virtual environment which improves their education through e-Learning. The virtual 3D environment is made with different imaging methods (helium-filled balloon, Structure for motion, 3D repository models) and a developmental plan has been designed for use in many future applications. Digital tools were used with 3D reconstructed buildings from the museum archive to Unity 3D for the design. The pilot study of Information Technology work has been employed to introduce cultural heritage and archaeology to university syllabuses. It included students with a questionnaire which has been evaluated accordingly. As a result, the university students were inspired to immerse themselves into the virtual lab, aiming to increasing the level of interaction. The results show a satisfactory learning outcome by an easy to use and real 3D environment, a step forward to fill in needs of contemporary online sustainable learning demands.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 358 ◽  
Author(s):  
Chiara R. M. Brambilla ◽  
Ogochukwu Lilian Okafor-Muo ◽  
Hany Hassanin ◽  
Amr ElShaer

Three-dimensional (3D) printing is a recent technology, which gives the possibility to manufacture personalised dosage forms and it has a broad range of applications. One of the most developed, it is the manufacture of oral solid dosage and the four 3DP techniques which have been more used for their manufacture are FDM, inkjet 3DP, SLA and SLS. This systematic review is carried out to statistically analyze the current 3DP techniques employed in manufacturing oral solid formulations and assess the recent trends of this new technology. The work has been organised into four steps, (1) screening of the articles, definition of the inclusion and exclusion criteria and classification of the articles in the two main groups (included/excluded); (2) quantification and characterisation of the included articles; (3) evaluation of the validity of data and data extraction process; (4) data analysis, discussion, and conclusion to define which technique offers the best properties to be applied in the manufacture of oral solid formulations. It has been observed that with SLS 3DP technique, all the characterisation tests required by the BP (drug content, drug dissolution profile, hardness, friability, disintegration time and uniformity of weight) have been performed in the majority of articles, except for the friability test. However, it is not possible to define which of the four 3DP techniques is the most suitable for the manufacture of oral solid formulations, because the selection is affected by different parameters, such as the type of formulation, the physical-mechanical properties to achieve. Moreover, each technique has its specific advantages and disadvantages, such as for FDM the biggest challenge is the degradation of the drug, due to high printing temperature process or for SLA is the toxicity of the carcinogenic risk of the photopolymerising material.


2017 ◽  
Vol 8 (2) ◽  
pp. 196-202 ◽  
Author(s):  
Kirsten Rose-Felker ◽  
Joshua D. Robinson ◽  
Carl L. Backer ◽  
Cynthia K. Rigsby ◽  
Osama M. Eltayeb ◽  
...  

Background: Computed tomographic angiography (CTA) and echocardiography (echo) are used preoperatively in coarctation of the aorta to define arch hypoplasia and great vessel branching. We sought to determine differences in quantitative measurements, as well as surgical utility, between modalities. Methods: Infants (less than six months) with both CTA and echo prior to coarctation repair from 2004 to 2013 were included. Measurements were compared and correlated with surgical approach. Three surgeons reviewed de-identified images to predict approach and characterize utility. Computed tomographic angiography radiation dose was calculated. Results: Thirty-three patients were included. No differences existed in arch measurements between echo and CTA ( z-score: −2.59 vs −2.43; P = .47). No differences between modalities were seen for thoracotomy ( z-score: −2.48 [echo] vs −2.31 [CTA]; P = .48) or sternotomy ( z-score: −3.13 [echo] vs −3.08 [CTA]; P = .84). Computed tomographic angiography delineated great vessel branching pattern in two patients with equivocal echo findings ( P = .60). Surgeons rated CTA as far more useful than echo in understanding arch hypoplasia and great vessel branching in cases where CTA was done to resolve anatomical questions that remain after echo evaluation. Two of three surgeons were more likely to choose the surgical approach taken based on CTA (surgeon A, P = .02; surgeon B, P = .01). Radiation dose averaged 2.5 (1.6) mSv and trended down from 2.9 mSv (1.8 mSv; n = 20) to 1.6 mSv (0.5 mSv; n = 7) ( P = .06) with new technology. Conclusion: Although CTA and echo measurements of the aorta do not differ, CTA better delineates branching and surgeons strongly prefer it for three-dimensional arch anatomy. We recommend CTA for patients with anomalous arch branching patterns, diffuse or complex hypoplasia, or unusual arch morphology not fully elucidated by echo.


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