Keeping Shale Formation Stability by Optimizing Drilling Fluids, in Yangta Oil Field, Western China

Author(s):  
Xiangjun Liu ◽  
Pinya Luo ◽  
Hong Liu ◽  
DaChuan Liang ◽  
Faqian Luo
2009 ◽  
Author(s):  
Xiangjun Liu ◽  
Pinya Luo ◽  
Hong Liu ◽  
DaChuan Liang ◽  
Faqian Luo

2019 ◽  
Vol 10 (3) ◽  
pp. 1215-1225
Author(s):  
Asawer A. Alwassiti ◽  
Mayssaa Ali AL-Bidry ◽  
Khalid Mohammed

AbstractShale formation is represented as one of the challenge formations during drilling wells because it is a strong potential for wellbore instability. Zubair formation in Iraqi oil fields (East Baghdad) is located at a depth from 3044.3 to 3444 m. It is considered as one of the most problematic formations through drilling wells in East Baghdad. Most problems of Zubair shale are swelling, sloughing, caving, cementing problem and casing landing problem caused by the interaction of drilling fluid with the formation. An attempt to solve the cause of these problems has been adapted in this paper by enhancing the shale stability through adding additives to the drilling fluid. The study includes experiments by using two types of drilling fluids, API and polymer type, with five types of additives (KCl, NaCl, CaCl2, Na2SiO3 and Flodrill PAM 1040) in different concentrations (0.5, 1, 5 and 10) wt% and different immersion period (1, 24 and 72 h) hours. The effect of drilling fluids and additive salts on shale has been studied by using different techniques: (XRD, XRF, reflected and transmitted microscope) as well shale recovery. The results show that adding 10 wt% of Na2SiO3 to API drilling fluid results in a high percentage of shale recovery (78.22%), while the maximum shale recovery was (80.57%) in polymer drilling fluid type gained by adding 10 wt% of Na2SiO3.


2014 ◽  
Vol 5 (1) ◽  
pp. 260-270
Author(s):  
Khoshniyat A ◽  
Shojaei M. ◽  
Jarahian K. ◽  
Mirali M. ◽  
Ghorashi S. ◽  
...  

A new experimental model was developed to predict the role of special polymeric additives, in the drilling fluid formulation, on the wellbore stability in shale formation. The shale formation was regarded as a non-ideal membrane and the effects of various characteristics of the added polymers were studied on the membrane reflection coefficient. The model was applied to unique field data from the oil field in south of Iran, including clay structure, cation exchange capacity (CEC), density and porosity of the shale. The results, using various polyglycols and polyacrylamides as the polymeric additive, showed that the structure of the polymeric chains e.g. type and content of ionic segments had significant effect on their adsorption mechanism and its strength.  It was concluded that increasing the molecular weight of the polymer chains decreased the rate and amount of the adsorption due to the increasing of the entanglements between the chains which in turn limited their mobility. So, adsorption of the polymeric material on the shale had significant impress on its performance as a membrane by increasing the shale reflection coefficient enhancing its stability during drilling process. Finally, the developed model results were in good agreement by experimental test results which was done in a specific shale stability set up.


Author(s):  
Yang Bai ◽  
Chunyan Liu ◽  
Guojun Li ◽  
Ren Wang ◽  
Dezhi Liu ◽  
...  

2021 ◽  
Author(s):  
Mohammed Alkhalifah ◽  
Rabih Younes

Abstract In an oil field, openhole multilateral maximum reservoir contact (MRC) wells are drilled. These wells are typically equipped with smart well completion technologies consisting of inflow control valves and permanent downhole monitoring systems. Conventional flowback techniques consisted of flowing back the well to atmosphere while burning the hydrocarbon and drilling fluids brought to surface. In an age of economic, environmental and safety consciousness, all practices in the petroleum industry are being examined closely. As such, the conventional method of flowing back wells is frowned upon from all aspects. This gives rise to the challenge of flowing back wells in an economic manner without compromising safety and the environment; all the while ensuring excellent well deliverability. By utilizing subsurface smart well completion inflow control valves, individual laterals are flowed to a separator system whereby solid drill cuttings are captured and discharged using a solids management system. Hydrocarbons are separated using a separation vessel and measured before being sent to the production line toward the field separation facility. Permanent downhole monitoring systems are used to monitor pressure drawdown and subsequently control the rate of flow to surface to ensure reservoir integrity. Following the completion of the solids and drilling fluid flowback from the wellbore, comprehensive multi-rate measurements at different choke settings are obtained to quantify the well performance. This paper looks at the economic and environmental improvements of the adopted zero flaring cleanup technology and smart well completions flowback techniques in comparison to conventional flowback methods. This ensures that oil is being recovered during well flowback and lateral contribution to overall flow in multilateral wells. In addition, it highlights the lessons learned and key best practices implemented during the cleanup operation to complete the job in a safe and efficient manner. This technique tends to set a roadmap for a better well flowback that fulfills economic constrains and protects the environment.


2017 ◽  
Vol 149 ◽  
pp. 59-66 ◽  
Author(s):  
Yurany Villada ◽  
Felipe Gallardo ◽  
Eleonora Erdmann ◽  
Natalia Casis ◽  
Laura Olivares ◽  
...  

1994 ◽  
Vol 58 (392) ◽  
pp. 401-408 ◽  
Author(s):  
G. M. Friedman ◽  
D. J. Schultz

AbstractVaterite, a CaCO3 polymorph, is a rare mineral that is said to be metastable under all known conditions. According to the literature, vaterite precipitated from carbonate solution recrystallizes spontaneously to calcite or aragonite. Yet vaterite has been identified in hard tissues of organisms, in gallstones, in contact metamorphic aureoles, in zones of thermal metamorphism, in a meteorite, and in cone-in-cone concretions. Newly precipitated vaterite has formed at the expense of carbonate rock in drilling fluids in wells of New York, Michigan, Nevada, Texas, and New Zealand. Petrographic examination reveals a light brown core of Ca3SiO5 surrounded by a colourless rim of vaterite. The δ18OPDB of New York vaterite is −12.4‰ and that of the Michigan vaterite is −17.6‰, which reflect the oxygen isotopic composition of meteoric freshwater used in drilling. The δ13CPDB value of −19.2‰ for New York vaterite and that of −17.6‰ for Michigan vaterite suggest that natural gas dissolved original carbonate in the subsurface. Drilling records from both wells indicate that natural gas was released into the drilling muds from the formations exposed at the time vaterite was encountered. Crossplots of the oxygen and carbon isotopic ratios overlap those of spurrite rocks in thermal metamorphic zones in Israel. A C-14 radiocarbon analysis of the Michigan vaterite gave an age of 953±39 yr. BP. 88.8±0.6% is modern carbon and 11.2% is dead carbon. Hence this carbon, and therefore the vaterite, is essentially modern. A sample of the New York vaterite yielded a modern age.


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