scholarly journals Classification and Application of Tight Gas Wells Based on Cluster Analysis

2021 ◽  
Vol 2095 (1) ◽  
pp. 012099
Author(s):  
Zhenhua Cai ◽  
Chuanshuai Zuo ◽  
Jianying Zhu ◽  
Peng Qin ◽  
Baojiang Duan ◽  
...  

Abstract The tight gas field is greatly affected by pressure in the development process. Due to the different production time and formation pressure of each well in the gas field, the production characteristics of the gas well are obviously different. After the gas well sees water, it is impossible to formulate production measures efficiently and accurately. Therefore, by analyzing the production performance characteristics of gas wells, this paper carries out the classification research of tight gas wells, and formulates the corresponding production measures according to the classification results. Taking gas well energy and liquid production intensity as the reference standard of gas well classification, the dynamic parameter indexes characterizing gas well energy and liquid production intensity are established. Gas wells with different production characteristics are divided into six categories by clustering algorithm: high energy-low liquid, high energy-high liquid, medium energy-low liquid, medium energy high-liquid, low energy-low liquid, low energy-high liquid. Then the classification method of tight gas well is formed. In this paper, 50 wells in Linxing block are selected as the research object. The research results show that most of the wells in Linxing block are located in area V, belonging to low energy and low liquid wells. It is recommended to implement intermittent production. The classification based on gas well energy and liquid production intensity are of guiding significance for the formulation of production measures in the Linxing block.

2012 ◽  
Vol 616-618 ◽  
pp. 762-766
Author(s):  
Rui Lan Luo ◽  
Ji Wu Fan ◽  
Hong Mei Liao ◽  
Wen Xu

Influenced by special geologic condition and stimulation, the production performance of tight fractured gas well is obviously different from that of conventional gas well. During deliverability testing, the hydraulic fractured gas well can never reach steady state with limited test time. It is difficult to calculate reserve and drainage area accurately at early development stage. Take eastern Sulige gas field for example, by correctly recognizing the percolation characteristics and production performance of hydraulically-fractured tight gas wells, and combined with core analysis, 116 hydraulically fractured tight gas wells in eastern Sulige gas field have been analyzed. A prediction chart of recoverable reserve for estern Sulige gas field is established. With this chart, the ultimately recoverable reserves, drainage sizes, drainage lengths and drainage widths of 116 hydraulically-fractured tight gas wells in eastern Sulige gas field are predicted based on early stage of production data, and finally a reasonable well spacing for this field is suggested. Only utilizing routine production data without employing additional resources, this method is a good predictive guide to launch a development plan of tight gas field.


2014 ◽  
Vol 884-885 ◽  
pp. 104-107
Author(s):  
Zhi Jun Li ◽  
Ji Qiang Li ◽  
Wen De Yan

For the water-sweeping gas reservoir, especially when the water-body is active, water invasion can play positive roles in maintaining formation pressure and keeping the gas well production. But when the water-cone break through and towards the well bottom, suffers from the influencing of gas-water two phase flows, permeability of gas phase decrease sharply and will have a serious impact on the production performance of the gas well. Moreover, the time when the water-cone breakthrough will directly affect the final recovery of the gas wells, therefore, the numerical simulation method is used to conduct the research on the key influencing factors of water-invasion performance for the gas wells with bottom-water, which is the basis of the mechanical model for the typical gas wells with bottom-water. It indicate that as followings: (1) the key influencing factors of water-invasion performance for the gas wells with bottom-water are those, such as the open degree of the gas beds, well gas production and the amount of Kv/Kh value; and (2) the barrier will be in charge of great significance on the water-controlling for the bottom water gas wells, and its radius is the key factor to affect water-invasion performance for the bottom water gas wells where the barriers exist nearby.


2019 ◽  
Vol 814 ◽  
pp. 505-510
Author(s):  
Peng Chang ◽  
Rui Xue Shi ◽  
Li Wang ◽  
Wei Han ◽  
Cong Dan Ye ◽  
...  

A large amount of foreign matter appears in the Sulige gas well, causing blockage and corrosion of the pipeline, increasing the pressure difference in the wellbore and seriously affecting the normal production of the gas well. The gas wells with serious conditions mentioned above were selected to analyze the quality of single well produced water and the composition of blockage and core. Combined with the XRD analysis results of the cuttings, the long-term leaching experiments on the cuttings in different simulated solutions were carried out to study the sources of scaled ions in the gas wells. The experimental results showed that the extracted water from SD6-1 had high salinity and high content of scale ions Ca2+, Ba2+ and Sr2+;the main component of blockage is the acid insoluble strontium sulfate (barium) scale, and contains a small amount of corrosion products. The easily scalable Ca2+、Mg2+、Ba2+ and Sr2+ produced from the dissolution of the core in the formation water or working fluids, especially the acid erosion dissolves. According to the scaling mechanism, two kinds of Sr/Ba scale inhibitor were selected. The results showed that the barium II scale inhibitor performance is relatively good, and at the concentration of 40 mg/L, and the scale inhibition rate was more than 95%. The clogging of a single well can be reduced by adding a scale inhibitor.


2021 ◽  
pp. 75-85
Author(s):  
D. S. Leontiev ◽  
I. I. Kleshchenko ◽  
A. D. Shalyapina ◽  
M. M. Mansurova

In the modern practice of gas field operation, there is a problem associated with the inflow of bottom water to the bottom hole of the well. One of the ways to solve this urgent problem is the introduction of water isolation technologies in the development of gas fields and the use of special compositions and technological equipment for pumping liquids into the watered layers of gas wells. The article deals with the application of a set of special technological measures, such as installation of surface equipment for working in a gas well using coiled tubing, descent of a flexible pipe through a column of pump and compressor pipes with a packer, construction of an inflatable packer, as well as the use of a selective water-insulating composition of the well by pumping it through existing perforation channels in the casing string. Liquids based on ethyl silicate create a kind water shut-off screen between the gas- saturated and water-saturated parts of the gas well formation.


2021 ◽  
Author(s):  
Yuan Liu ◽  
Bin Li ◽  
Hongjie Zhang ◽  
Fan Yang ◽  
Guan Wang ◽  
...  

Abstract The economics of tight gas fields highly depend on the consistency between expected production and the actual well performance. A mismatch between the reservoir quality and the well production often leads to a review of the individual well. However, such mismatch may vary from case to case, and it is hard to perform a field-level analysis based on individual well reviews. We introduce a new method based on data mining to assist the field-level diagnosis. LX gas field is located the in eastern Ordos basin. Compared to the main gas field in the center of the basin, LX field is less predictable in well performance. This predictability issue hinders field development in LX field because the field economics are substantially jeopardized by the inconsistency between the reservoir quality and the production performance. The traditional workflow to understand this issue at the field level is to review the details of a large number of individual wells in the area. This is typically an intense task, and too much detail from multiple disciplines may hide the true pattern of the field behavior. To resolve this issue, we applied data mining in our field development diagnosis workflow. Our new workflow in LX area started with the existing field datasheet, including logging summaries, completion treatment reports, and flowback testing datasheets. With the data extracted from these different sources, we visualized the consolidated information in various plots and graphs based on regression analysis, which revealed the relation between flowback ratio and the production, the flowback rate consistency from the different service suppliers, and the impact of water productions. The data mining approach helped to generate new understandings in LX gas field. With the in-depth analysis of the flowback data together with reservoir properties and operation parameters, the key problems in the field were identified for further development optimization, and the field economics can be significantly improved. The diagnosis method can be easily adapted and applied to any field with similar problems, and data mining can be useful for almost all large-scale field development optimizations.


2006 ◽  
Vol 82 (5) ◽  
pp. 739-750 ◽  
Author(s):  
F. Quevedo ◽  
C. Cervera ◽  
E. Blas ◽  
M. Baselga ◽  
J. J. Pascual

AbstractA total of 166 crossbred does were used to study the possible long term effect of two types of crossbred does (H1 v. H2, old and current generations, respectively) from the cross of different generations of lines selected for litter size, the use of a feeding programme based on a low-energy diet during the rearing and the administration of a high-energy diet during reproductive life, on the performance and body condition of multiparous pregnant does. Selection did not affect the live weight (LW) of does at the effective artificial insemination (AI; 4257 g), the LW change (+12·3 g/day) and food intake (172 g dry matter (DM) per day) until the 28th day of pregnancy. However, H2 does showed greater LW losses during the pre-partum period than H1 does (120+g;P<0·05), perhaps related to their higher prolificacy (+1·1 total pups born;P<0·05). H2 does showed a higher perirenal fat thickness (PFT) at first AI (+0·12 mm;P<0·05) than H1 does, these differences disappearing at effective AI. Females given a high-energy reproduction diet showed a lower LW at effective AI than those receiving a medium-energy diet (4210, 4305 g, respectively;P<0·05). However, type of reproduction diet did not affect the LW and PFT changes of pregnancy does, reaching partum with a similar PFT (8·83 v. 8·93 mm) and maintaining the differences in LW. Pregnant does given high-energy diet consumed 20 g DM and 1·4 g digestible protein per day less than does receiving medium-energy diet until the 28th day of pregnancy, but their digestible energy (DE) intake was significantly higher (+78 kJ DE per day;P<0·05). Does given high-energy diet showed a significantly lower litter size at birth (−0·7 pups;P<0·05), although there were no significant differences in the number of pups born alive (9·54 and 9·76 pups for high and medium-energy diets, respectively). Pups from does given high-energy diet were slightly weightier than those from medium-energy diet (+5·4 g;P<0·05). Multiparous pregnant does that received a low-energy diet ad libitum during the rearing period and first pregnancy showed a higher LW at effective AI (+137 g LW;P<0·05) but a lower PFT (−0·26 mm;P<0·05) than those females that received a medium-energy diet restricted during this same period. These differences were maintained at parturition (+142 g LW and −0·20 mm;P<0·05). Feeding programme during rearing affected neither the food intake of multiparous pregnant does until the 28th day of pregnancy, nor the litter size and weight at birth. The interval between parturitions was not affected by the selection for litter size or the reproduction diet received, but was longer for does that received the low-energy diet ad libitum during the rearing period (+2·9 days;P<0·05). In conclusion, rabbit selection programmes by litter size seem to be working well, but high energy reproduction diets, frequently used to cover their higher energy requirements, must be used carefully out of lactation in the long term to avoid a reduction in litter size.


2021 ◽  
Vol 22 (Supplement_3) ◽  
Author(s):  
I Casans Tormo ◽  
R Ruiz Granell

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Clinic Hospital of Valencia Aim The assessment of cardiac sympathetic innervation by 123I-metayodobenzylguanidine (123I-MIBG) has proved useful in patients with heart failure and neurodegenerative disorders. The standard quantification of global cardiac uptake is to obtain the heart to mediastinum (HM) ratio in planar images, while SPECT images provide better evaluation of regional extent of denervated areas. Although low energy (LE) collimator has been widely used in these patients, septal penetration of high-energy photons of 123I could affect image quality and quantification accuracy. We have compared in the same patients the effect of collimator type on image quality and quantitative assessment of HM ratio. Methods In a group of 14 patients (11 men, 57-77 y/o, 66.4 ± 5.6) submitted for cardiac sympathetic study, we obtained successive planar anterior chest images 4h after the IV administration of 10 mCi of 123I-MIBG with a low-energy-high-resolution (LEHR) and a medium-energy (ME) collimators. Images were obtained with the same gammacamera Brightview Philips for 10 min on 256x256 matrix, with 159 Kev photopeak and unchanged patient position. For quantification of HM ratio, we use in each patient the same manual heart ROI and rectangular upper mediastinum ROI in the two acquired images to obtain the corresponding HM ratio. Results The image quality was better in all the patients with ME collimator acquisition than with LEHR collimator acquisition, and the HM ratio showed higher values with ME: 1.65-2.61 (mean 2.15 ± 0.28) than with LEHR: 1.27-1.85 (mean: 1.51 ± 0.18) with a mean difference of 0.64 ± 0.15 (0.38-0.88) between ME and LEHR and a mean ratio LEHR/ME of 0.70 ± 0.04 (0.64-0.79). In 9 patients with HM ratio ≤ 1.60 obtained from LEHR collimator acquisition, the mean difference with HM ratio obtained with ME collimator was 0.61 ± 0.12 and mean ratio LEHR/ME was 0.69 ± 0.03 and in 5 patients with HM ratio(LEHR) &gt;1.60, mean difference with HM ratio(ME) was 0.69 ± 0.19 and mean ratio LEHR/ME was 0.71 ± 0.02. Conclusion Use of a ME collimator provides better image quality than LEHR collimator in planar images and higher values of HM ratio, providing a more accurate quantification of cardiac uptake in the patients submitted for evaluation of cardiac sympathetic innervation by 123I-MIBG, and could also improve the evaluation of regional impairment and extent of denervated areas by SPECT.


2021 ◽  
Vol 329 ◽  
pp. 01013
Author(s):  
Linqing Liu ◽  
Shuo Zhai ◽  
HaiTao Li ◽  
Jing Wang

Hydraulic fracturing horizontal well is the key technology of tight gas development. After fracturing, the gas well shows the characteristics of great difference in production energy and many factors affecting production capacity. Therefore, taking 10 fractured horizontal wells in JQ gas field in Sichuan Basin as an example, comprehensively considering the influence of geological and engineering factors, and based on the statistical analysis of gas well productivity and the laws of various index parameters, 17 geological and engineering parameters were selected, and the main factors controlling productivity were studied by grey correlation method. The results show that the tight gas fracturing horizontal well can obtain high production, which is jointly determined by geological and engineering factors. The five main control factors affecting the productivity of tight gas fracturing horizontal well are as follows: proppant type, preflush, ϕ·h. Sand volume and reservoir volume.


2012 ◽  
Author(s):  
Zhu Tianshou ◽  
Gangdan Fu ◽  
Yong Ren ◽  
Huaguang Zhang ◽  
Fenxia Zhao ◽  
...  

2013 ◽  
Vol 868 ◽  
pp. 692-695
Author(s):  
Hong Lian Li ◽  
Rui Dai ◽  
Xiao Lu Wang ◽  
Ji Feng Qu

Sebei NO.2 gas field I-1 layer group is shallow-buried with comparatively lower formation energy. In the process of developing, the formation pressure drops and the total energy consumption of the gas-liquid two phase pipe flowing increases gradually, which leads wellbore to produce accumulated fluid that greatly reduces gas well productivity. This paper is based on the mastery of gas field reservoir characteristics and production dynamics, analyzing the changes of gas well production performance before and after gas wells with accumulated fluid. A wellbore liquid loading identification model of Sebei NO.2 gas field is established in terms of the liquid removing capacity calculations, wellhead characteristic observation method, the pressure gradient method. In the aspect of liquid loading volume, the study based on the theory of wellbore gas-liquid two phase flow, using four classical pressure distribution models to construct a combined model that is more suitable for single wells, analyzed the features of fluid gas well distribution with structural characteristics and other aspects. Practical application shows that the analysis results are reliable and highly practical, and deepening the understanding of the phenomenon of gas liquid loading.


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