Application of Multistage Hydrajet-Fracturing Technology in Horizontal Wells with Slotted Liner Completion in China

2014 ◽  
Author(s):  
Qu Hai ◽  
Zhao Xiaoxiang

Abstract Multistage hydrajet-fracturing combines hydrajet perforating and hydraulic fracturing to perform separate, sequential fracture stimulations without mechanical packers. It can reasonably place fractures according to geological condition, and then accurately treat them. Without packer, it uses dynamic isolation to seal flow into target, saving operating time and lowering operating risk. Therefore, the process not only especially adapts to stimulate open hole, but effectively treats slotted liner completion. The mechanisms and fluid dynamics of multistage hydrajet-fracturing technology are investigated with numerical simulation and laboratory experiments. More than 70 oil and gas wells have been successfully treated using this technology since 2009. On average, three hydraulic fractures with total 120m3 proppants were placed at strategically selected locations in well, typically several hundred meters apart without sealing equipments. The deepest treatment in oil well 203-19 in Zhongyuan oilfield, using tubing string, was 3692m, and surface pressure reached 88MPa. Significant stimulation results were achieved in these wells. For example, production increased by more than 50 times after stimulation to the gas well XS311H in Sichuan oilfield. The oil well 92-2 in the Zhongyuan oilfield, which had been a dead horizontal well, has been revived using this technology with average oil production of 15 tons per day. Multistage hydrajet-fracturing stimulation shows promising feature for horizontal, vertical, deviated, and even multilateral wells.

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. D209-D222 ◽  
Author(s):  
David Pardo ◽  
Carlos Torres-Verdín

We numerically evaluate the possibility of using borehole electromagnetic measurements to diagnose and quantify hydraulic fractures that have been artificially generated in a horizontal well. Hydrofractures are modeled as thin disks perpendicular to the well and filled with either sand-based or electrically conductive proppant. The study focuses on the effect of thickness and length (radius) of hydrofractures to assess their effects on specific configurations of borehole-resistivity instruments. Numerical results indicate that several measurements (e.g., those obtained with low- and high-frequency solenoids) could be used to assess the thickness of a fracture. However, only low-frequency measurements performed with electrodes and large-spacing between transmitter and receivers (18 m) exhibit the necessary sensitivity to reliably and accurately estimate the length of long hydrofractures (up to 150 m) in open-hole wells. In the case of steel-cased wells, the casing acts as a long electrode, whereby conventional low-frequency short-spaced, through-casing measurements are suitable for the accurate diagnosis of long hydrofractures (up to 150 m in length).


1998 ◽  
Vol 45 (3) ◽  
pp. 148-152 ◽  
Author(s):  
C. Jeyaprabha ◽  
S. Muralidharan ◽  
D. Jayaperumal ◽  
G. Venkatachari ◽  
N.S. Rengaswamy

To reduce the corrosion of oil‐ and gas‐well equipment during acid treatment, the acid must be inhibited. The behaviour of N‐80 oilfield material in 15 per cent hydrochloric acid solution inhibited by different inhibitor formulations containing amine, ester and a quaternary ammonium compound was studied at 303K for five hours by the mass loss method. The corrosion rates were obtained by polarisation. Impedance studies were carried out to evaluate the performance of the inhibitor formulations. It was found that the formulation containing 3,000ppm amine, 1,000ppm ester and 1,000ppm quaternary ammonium compound was effective for the specific oil‐well tubular material.


2005 ◽  
Vol 127 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Y. Ding ◽  
G. Renard

It is well recognized that near-wellbore formation damage can dramatically reduce well productivities, especially for open hole completed horizontal wells. The economic impact of poor productivity of these wells has pushed toward significant efforts in recent years to study laboratory testing techniques and numerical modeling methods for predicting and controlling drilling-induced formation damage. This paper presents an integrated approach, combining a near-wellbore modeling with laboratory experiments for data acquisition as input for the model, to evaluate the performance of oil and gas wells after drilling-induced formation damage.


2020 ◽  
pp. 014459872096410
Author(s):  
Qimin Liang ◽  
Bairu Xia ◽  
Baolin Liu ◽  
Baokui Gao

The multistage stimulation technique and horizontal wells are increasingly being utilized to improve oil and gas recovery. However, the sticking that occurs due to large drag during the completion string with packers tripping into the horizontal section, resulting in an abandoned well and huge economic losses. Based on a classical drag model, this paper illustrates how local drags affect the overall stress of the completion string by a case study. Mechanical models are also presented for analyzing the local drag of packers in horizontal sections considering the effects of microsteps or slots, borehole curvatures, and caliper variation respectively. The results confirmed that the local contact force is affected by centralizers, and local drags can be magnified during their upward transmission process. It is revealed that the slopes of microsteps or slots affect more on local drag of packers than the effects of microsteps’s height and slots’ depth; Moreover, the local drag of the packer was found increases with the increase of the borehole curvature, but less affected by the caliper variation; As to the effect of cuttings on the local drag of packers, it is affected by cuttings size and cuttings amount and cannot be quantitatively analyzed. This research could be utilized as a theoretical reference for estimating the sticking risks of the completion string and conditioning the horizontal open hole.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5585
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Faisal Khan ◽  
Mohammad Azizur Rahman ◽  
Amer Aborig ◽  
...  

Oil and gas well productivity can be affected by a number of different skin factors, the combined influences of which contribute to a well’s total skin factor. The skin caused by deviated wells is one such well-known factor. The present study aimed to investigate skin effects caused by deviated well slants when considering vertical-to-horizontal permeability anisotropy. The research employed computational fluid dynamics (CFD) software to simulate fluid flows in inclined wells through the injection of water with Darcy flow using 3D geometric formations. The present work investigates the effects of four main characteristics—namely, the permeability anisotropy, wellbore radius, reservoir thickness, and deviation angle—of open-hole inclined wells. Additional investigations sought to verify the effect of the direction of perforations on the skin factor or pressure drop in perforated inclined wells. In the case of an inclined open hole well, the novel correlation produced in the current study simplifies the estimation of the skin factor of inclined wells at different inclination angles. Our comparison indicates good agreement between the proposed correlation and available models. Furthermore, the results demonstrated a deviation in the skin factor estimation results for perforated inclined wells in different perforation orientation scenarios; therefore, existing models must be improved in light of this variance. This work contributes to the understanding and simulation of the effects of well inclination on skin factor in the near-wellbore region.


2008 ◽  
Vol 11 (05) ◽  
pp. 902-911 ◽  
Author(s):  
Flavio Medeiros ◽  
Erdal Ozkan ◽  
Hossein Kazemi

Summary This paper discusses the performance and productivity of fractured horizontal wells in heterogeneous, tight-gas formations. Production characteristics and flow regimes of unfractured and fractured horizontal wells are documented. The results show that if hydraulic fracturing affects stress distribution to create or rejuvenate natural fractures around the well, the productivity of the system is significantly increased. Unless there is significant contrast between the conductivities of the hydraulic and natural fractures, hydraulic fractures may not significantly contribute to the productivity. For extremely tight formations, the effective drainage area may be limited to the naturally fractured region around the well and the hydraulic fractures. It is also shown that very long transient flow periods govern the productivity and economics of fractured horizontal wells in tight formations. The results of this study are also applicable to oil production from fractured shale. Introduction Economic gas and oil production from low permeability reservoirs has been a challenge for the oil and gas industry. Because most of the high permeability reservoirs have been exploited and many low permeability reservoirs remain undeveloped, the latter have taken the industry attention recently. Particular attention has been given to tight-gas reservoirs with permeability in the range of micro-Darcies or below and to oil accumulation in fractured shale. Hydraulically fractured horizontal wells are the proven technology to produce oil and gas from tight formations. Hydraulic fractures reduce well drawndown, increase the productivity of horizontal wells by increasing the surface area in contact with formation, and provide high conductivity paths to the wellbore. Depending on in-situ stress orientation, hydraulic fractures can be parallel (longitudinal) or perpendicular (transverse) to horizontal well axis. Project economics in tight formations, however, depends strongly on well spacing and the number of hydraulic fractures required to drain the reservoir efficiently. Field evidence indicates that the drainage areas of fractured horizontal wells in tight formations may be limited to a rectangular region confining the horizontal well and the transverse hydraulic fractures. Also, there has been evidence that hydraulic fracturing in tight formations changes stresses in fracture drainage area, which could create or rejuvenate natural fractures in the near-vicinity of the horizontal well. This fracture network, which may be characterized as a dual-porosity system, may contribute significantly to improve productivity of the fractured horizontal well. Much work has been done (Soliman et al. 1990; Larsen and Hegre 1994; Temeng and Horne 1995; Raghavan et al. 1997; Wan and Aziz 1999; Al-Kobaisi et al. 2006) to investigate pressure-transient analysis and short- and long-term productivity of horizontal wells with single or multiple hydraulic fractures. The effect of a dual-porosity zone surrounding hydraulic fractures, however, has not been considered in the previous studies. The main objective of this study is to investigate the combined effects of a dual-porosity region and hydraulic fractures on the productivity of horizontal wells. The results presented in this work are based on a semianalytical model developed by Medeiros et al. (2006). The model was derived from the Green's function formulation of the solution for the diffusivity equation (Gringarten and Ramey, 1974, Ozkan and Raghavan, 1991a, 1991b) and has the capability to incorporate local heterogeneities. In this work, we use the semianalytical model to incorporate induced finite-conductivity fractures (transverse and longitudinal) along the horizontal well and naturally fractured zones around the hydraulically fractured horizontal well by using the dual-porosity idealization. We use the example data sets given in Tables 1 through 3 to consider different cases of horizontal wells with and without induced and natural fractures.


2013 ◽  
Vol 416-417 ◽  
pp. 1895-1898
Author(s):  
Yan Wang

As an emerging technology in the field of oil and gas well project, oil and gas well expansion pipe could maximally reduce the hole size decrease resulting from reduced catheter column of the wellbore, so as to achieve the purpose of saving costs. Meanwhile, this technology brings good news to Nerve well drilling in complicated geological condition and improvement of well structure. This article starts from the working principles of expansion pipe, and puts emphasis on the key technologies of expansion pipe and gives a detailed analysis of the application of expansion pipe technology.


2017 ◽  
pp. 30-36
Author(s):  
R. V. Urvantsev ◽  
S. E. Cheban

The 21st century witnessed the development of the oil extraction industry in Russia due to the intensifica- tion of its production at the existing traditional fields of Western Siberia, the Volga region and other oil-extracting regions, and due discovering new oil and gas provinces. At that time the path to the development of fields in Eastern Siberia was already paved. The large-scale discoveries of a number of fields made here in the 70s-80s of the 20th century are only being developed now. The process of development itself is rather slow in view of a number of reasons. Create a problem of high cost value of oil extraction in the region. One of the major tasks is obtaining the maximum oil recovery factor while reducing the development costs. The carbonate layer lying within the Katangsky suite is low-permeability, and its inventories are categorised as hard to recover. Now, the object is at a stage of trial development,which foregrounds researches on selecting the effective methods of oil extraction.


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