BOTTOM-HOLE PRESSURES CALCULATION METHOD FOR NATURALLY FLOWING OIL WELL AND ITS APPLICATION TO WELL TESTING COSTS REDUCTION

2015 ◽  
pp. 199-217
Author(s):  
V.E. Sova ◽  
E.V. Sova
2012 ◽  
Vol 560-561 ◽  
pp. 1188-1194
Author(s):  
Jun Tai Shi ◽  
Xiang Fang Li ◽  
Lei Zhang ◽  
Wei Na Ren ◽  
Le Zhong Li ◽  
...  

For a case of constant-rate liquid production from a single well centered in a horizontal, homogeneous-acting, isopachous, and infinite reservoir, based on fundamentals of fluid flow in porous media the bottom hole flowing pressure never stabilize. In the process of field well testing, however, pressure values measured by the pressure gauge which has a definite resolution value will not change after a period, so the bottom hole flowing pressure can be considered to be stabilized. According to this situation, through theoretical derivation, a stabilized time formula is firstly proposed, by which the time after which the bottom hole flowing pressure measured with a pressure gauge will be stabilized can be calculated, and the stabilized time for a given pressure gauge is in direct proportion to the liquid producing rate, but in inverse proportion to the resolution ratio of the pressure gauge. Applied the stabilized time formula, a new formula of detectable radius can be derived, by which the effect of resolution of the pressure gauge can be considered. Secondly, the time after which the value of the pressure gauge measured in the bottom hole of the observation well starts to change during interference testing is obtained, and the time is related to the fluid flow rate and the distance between the producing well and the observation well. The conclusion can be applied as a reference in the design process of working system during well testing.


2018 ◽  
Author(s):  
Preveen Kumar Rajan Preveen ◽  
Adhi Naharindra Adhi ◽  
Shazana M Zaki Shazana ◽  
Mior Yusni Mior ◽  
Nurbaiti Baharuddin Nurbaiti
Keyword(s):  

2002 ◽  
Author(s):  
Chris Fair ◽  
Betsy Cook ◽  
Tom Brighton ◽  
Michael Redman ◽  
Stacy Newman
Keyword(s):  
Oil Well ◽  

2020 ◽  
Vol 21 (6) ◽  
pp. 337-347
Author(s):  
A. H. Rzayev ◽  
G. A. Guluyev ◽  
F. H. Pashayev ◽  
As. H. Rzayev ◽  
R. Sh. Asadova

This paper presents a proposed new indirect method determining instantly oil well debit using developed mathematical models. As a result integrated analysis using the models it has been revealed correlation between oil well debit and well throw out flow temperature. Therefore putting purpose was obtained. Mathematical models are developed for the distribution of fluid flow temperature along the length of the tubing from the well bottom to the wellhead and along the length of the oil pipeline from the collector of oil wells to the oil treatment unit. On the basis of experimental data, the authors propose formulas in the form of the relationship between oil emulsion (OE) viscosity, the flow temperature and concentration of water globule in OE and the coefficient of heat transfer from the fluid flow in the wellbore (WB) to the rock, and heat capacity and thermal conductivity of gas, water, rock and steel of the WB walls. This effect is demonstrated in the constructed diagrams. It is shown bottom temperature jump as a result of the Joule Thomson drosseling effect then connective transmitted up at flow rate v. In such case well-head or well outlet oil mixture (OM) flow temperature depend more of volume of stream flow than of bottom hole temperature. Thought in the paper, do not taking into consideration great casing annulus areas influence to the well outlet flow temperature. As shown from supporting paper the relative values og the thermal conductivity of the liquid column and gas column present in the casing annulus order less than well bore (WB) wall thermal conductivity. Consequently well outlet OM flow temperature will depends not only of the volume of stream flow, also of the bottom hole temperature and of the gas column and liquid column.A new method for determining the oil well flow rate by measuring the downstream temperature is developed. A mathematical model is proposed that allows calculating the thermal profile of the fluid along the wellbore for determining the oil well flow rate with account of the geothermal gradient in the rock surrounding the wellbore. It is shown, that unlike the existing methods the new proposed method allows determining the instantaneous discharge of a well very easily. One of the actual challenges in fluid (oil, water and gas) transportation from wells to oil treatment installation is determination of a law of temperature distribution along the length of a pipeline at low ambient temperature. That temperature leads to increase in viscosity and deposition of wax on inner surface of a pipe. To overcome that challenge it is needed to consider several defining characteristics of formation fluid (FF) flow. Complexity of a solution is caused by two factors. From the one hand, in most cases (especially on a late stage of field development) FF is an oil emulsion (OE) that contains gas bubbles. From the other hand, temperature gradient between fluid flow and the environment has significant value (especially in the winter period of the year). At the same time, the higher content of emulsified water droplets (EWD) in OE and lower flow temperature, the higher FF viscosity, and consequently productivity (efficiency) of oil pumping system is reduced. Performed research and analysis of field experimental data showed that a function of oil viscosity versus temperature has a hyperbolic law; a function of OE viscosity versus concentration of EWD has a parabolic one. A heat balance for a certain section of a pipeline in steady state of fluid motion using a method of separation of variables was established taking into account above mentioned factors, Fourier’s empirical laws on heat conductivity and Newton’s law on heat transfer. As a result, unlike existing works, an exponential law of distribution of temperature along the length of a pipeline is obtained. A law takes into account nonlinear nature of change in viscosity of OE from change in temperature of flow and concentration of water in an emulsion. As a result, in contrast to the existing works, the proposed exponential law of temperature distribution along the length of the pipeline is obtained, taking into account the nonlinear nature of variation of OE viscosity with the change in the flow temperature and the concentration of water in the emulsion. The results of the calculation are presented in the form of a table and graphs.


2012 ◽  
Vol 594-597 ◽  
pp. 2602-2606
Author(s):  
Yu Zhao ◽  
Kao Ping Song ◽  
Yin Feng Liu

According to existing fluid-solid coupling models, reasonable range and control technology of pressure depression cone has not be formed in Putaohua reservoir. In this paper, using laboratory experiment, the relationship between rock elastic-plastic deformation, single phase permeability of oil or water and relative permeability curves has been measured and the following important facts has been established: oil well bottom hole pressure which is lower than formation pressure is in a reasonable range during the initial stage of commissioning, and a gently pressure depression cone is formed between the formation and wellbore, that can reduce the permeability loss by compaction settlement and particle migration and return to production in reasonable bottom hole pressure while the water flooding takes effect and thus enhance the oil recovery.


2019 ◽  
Vol 3 (2) ◽  
pp. 41-51
Author(s):  
Maha Hamoudi ◽  
Akram Humoodi ◽  
Bashdar Mohammed

Production logging tools (PLTs) in oil and gas industries are used for obtaining fluid types and measuring fluid rates in the borehole for both production and injection wells and to better understand the well productivity or the well injectivity of the interest zones. Additionally, it can be used to detect well problems, such as early water or gas breakthrough, channeling behind casing or tubing, and water or gas coning. The Khurmala field is a big oil field in the Kurdistan region of Iraq. PLTs have been acquired in many of the Khurmala oil wells, and the log records took into consideration the production technique decisions. In this study, results of the PLT log will be discussed in one of the Khurmala oil wells. Owing to the long history of production of oil or gas wells, many problems have been seen, such as coning either water or gas, formation damage, casing corrosion, and well obstruct. This research will evaluate the production profile across the slotted liner interval of (W1) well in the Khurmala oil field in the Iraq-Kurdistan region and detect possible water entry points, verify the distribution and nature of fluids, and estimate fluid segregation after the shut-in period. This was done by applying PLTs and interpreting the data by using Emeraude software. The performance of each choke size was studied and assessed. It was found that a choke size of 48/64̎gives the best favorable production gas, oil ratio, and profile. Results from the PL survey showed that no water entry was detected across the logged interval. All the water was coming from below a depth of 990 m; most of the hydrocarbons were coming from the slotted interval across 981.8-982.9 m, and the flowing pressure across the logged interval using maximum choke was less than the saturation pressure.


1999 ◽  
Vol 121 (3) ◽  
pp. 183-188
Author(s):  
A. S. Yigit ◽  
M. D. Al-Ansary ◽  
M. Khalid

The mode localization phenomena in bottom-hole assemblies (BHA) used in oil-well drilling is investigated. A fully gaged stabilizer model is shown to produce weak coupling between segments of drillcollars separated by stabilizers. It is observed that in a weakly coupled BHA, small disorder in span length can cause strong mode localization. For the first time, it is demonstrated that gravity induces a stiffness disorder, which in turn causes strong mode localization in an inclined wellbore, even though no other disorder is present. The effect of localized modes for failure is presented by examining the maximum bending stresses with and without mode localization. The results show that design and operation of drillstrings should consider the possibility of mode localization for an accurate prediction of dynamic behavior.


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