A Well Control Procedure for Wells with High Rate Upward Crossflow

2018 ◽  
Author(s):  
Mohamed M. El-Nekhily ◽  
Nasser M. Al-Hajri ◽  
Ibraheem M. Al-Ageel ◽  
Ibrahim A. Al-Obaidi
2021 ◽  
Author(s):  
Irma Kusumawati ◽  
Birger Heigre ◽  
Hunter Whitfield ◽  
Samuel Bremner ◽  
Andrea Sbordone ◽  
...  

Abstract This paper describes the utilization of a riserless light well intervention (RLWI) vessel with well control system and flexible downlines to execute a re-stimulation campaign on subsea injection wells located in the Norwegian Continental shelf in the summer of 2019 and 2020. A riserless light well intervention (RLWI) vessel with well control system and flexible downlines was used in combination with a stimulation vessel. The objective of each campaign was to increase injectivity in the wells with high-rate acid treatments. The lessons learned from the 2019 campaign were applied to the 2020 campaign, resulting in reduced health and safety exposure, and improved operational efficiency. Analysis of the treatments and their impact on injection and field pressure support was conducted to assess the effects of these improvements and provide insights for how the treatments can be applied to vessel stimulation in general. In each campaign, the RLWI vessel was connected to the subsea asset, and a dedicated stimulation vessel provided stimulation fluids via a high-pressure flexible hose connected between the two vessels. Both campaigns saw high treatment pump rates of up to 60 bbl/min with low-pH crosslinked gel fluids, 28% hydrochloric acid, and diverters in the form of ball sealers and rock salt. Hose deployment methodologies between the two vessels differed in the two campaigns. The 2019 campaign employed a conventional transfer utilizing the marine crane on the RLWI vessel to lift and lower the hose into a preexisting hanger. Learnings from this operation led to the development and use of a winch pull-in method in which the hose connection was accomplished with a hot stab connector on the RLWI vessel, eliminating human intervention and the use of the crane. The 2019 and 2020 campaigns successfully stimulated five and six subsea injection wells, respectively, and realized post-stimulation improvement in injection rates of 135%. One year of field monitoring from the first campaign shows pressure support benefits with improvements in production throughout the connecting area of the field. The winch pull-in method of hose deployment between the vessels achieved time improvements of 8 hours per stimulation treatment. In addition, the added flexibility of not needing to be within crane reach gave the operation extended working weather limits. The overall result was a significant improvement in operating efficiency between the 2019 and 2020 campaigns. The operations showed how high-rate stimulation can be achieved on subsea assets with the use of an RLWI and stimulation vessels. Detailed analysis of the operational efficiency of each campaign was performed, and the improvements from one campaign to the next documented. The winch pull-in method is a new way of high-pressure hose transfer that can be applied to future stimulation vessel operations to improve operational safety and efficiency.


1992 ◽  
Vol 7 (04) ◽  
pp. 247-253
Author(s):  
S. Miska ◽  
F.E. Beck ◽  
B.S. Murugappan

2021 ◽  
Author(s):  
Gehad Mahmoud Hegazy

Abstract In challenging times of 2020 and inconsistency with the background of a low-oil-price environment, innovative ideas needed to give a second life to all available resources such as unconventional, shallow, depleted, mature, heavy oil and by bypassed oil with a cost-effective manner (usually innovation created to fit needs). U-shaped well a combined with pigging lifting (conceptual study for new artificial lift method) is one of the selected scenarios studied under the objective of innovative, low-cost techniques to overcome many projects challenges. U shaped well accompanied with a new pigging artificial lift method are new concept studied in this lab work. Conceptual model presents many benefits of this new application such as solving most of the current wells and production challenges. The study reflects more well control with two paths, better well stimulation, low fracturing pressure and double rates, inject and lift chemical for clean without intervention, double well life "additional strings", new recompletions without rig, two horizontal side used for production or injection, step change for reservoir monitoring, improving artificial lift performance and allow creating Pigging lift "New artificial lift concept". U shaped well accompanied with a new pigging artificial lift method study shows the following progress: 1. Additional down hole barrier from the deepest point and additional open side keep the well under control more over minimize the existing well control killing procedures with low cost and risk in addition to discarding the CT operations for killing or prepare the well for W/O. 2. Decreasing stimulation pressures needs (double injection rates) and overcome the existing accessibility challenges 3. Allowing pull heading stimulation w/less displacement time and high rate and chimerical batch pumping from one side to another increase well life and eliminate PKRs risk as chimerical batches will be pigger, easier and faster. 4. Additional down hole monitoring system allowing uniform stimulation and discarding the CT operations for well stimulation and cleaning, 5. Avoiding post stimulation damage throughout fast clean-up 6. Ability to stimulate from one side with artificial lift from other side Avoiding the corrosion and erosion by faster operations 7. Allow faster plug and perf. multistage fracturing technology and overcome the unconventional well fracturing which required rate and pressure 8. Eliminate rig usage to pull the frac string to run completions 9. Step change for reservoir mentoring without S/D and real-time Logging, Sampling The deployment of U Shaped Well allows new artificial lift concept (Pigging lift) to apply. This new approach led to improved wells performance also raising efficiency of the use of the existing resources besides saving time and in return cost. This approach helps in improving well utilization and efficiency levels.


Author(s):  
Amare Leulseged ◽  
Sima A. Nepal ◽  
Dan Sui ◽  
Suranga C. H. Geekiyanage

In drilling operations, the downhole pressure (BHP) requires to be closely monitored and precisely managed to avoid potential drilling events harmful to personnel and environment. If the BHP is lower than the pore pressure, kick (amount of influx) from formation will enter the wellbore, which might result in (underground) blowout. If not properly managed, this could be more costly than surface blowouts [1]. Well control aims to stop and remove the influx and re-establish primary barriers. Managed Pressure Drilling (MPD) is an advanced drilling technology capable of precisely controlling annular pressure profile throughout the wellbore. In this study, a high fidelity transient flow model is used for simulating dynamic well control procedure in MPD to properly manage annular pressure during kick circulation after the kick is detected. In this work, an automated well control in MPD is simulated, where PID control algorithm is implemented by manipulating choke valve opening to dynamically regulate the BHP during kick circulation. The main aim is to investigate dynamic kick management with the use of different type of muds, water based mud (WBM) and oil based mud (OBM). For different mud systems, the well control performances for long extended reach wells are evaluated and compared. From simulations, it shows that the OBM is able to hide the influx to a large extent, than the WBM due to the much higher gas solubility of the OBM. In HPHT wells, the OBM is superior to the WBM with proper automatic surface pressure control in MPD operations. Using complicated dynamic flow model can provide more precisely surface pressure control for realtime dynamic kick management.


Author(s):  
Tim Nedwed ◽  
Doug Mitchell

Abstract There are still concerns about well control especially for operations in sensitive environments. Currently the final barrier while drilling oil and gas wells is a valve system (blowout preventer or BOP) located on top of wells. These valves can isolate wells by sealing around or shearing through obstructions in the well (e.g. drilling pipe and casing). If these valves fail or if some other barrier in a well fails, hydrocarbon loss to the environment is possible. Adding barriers capable of responding to a well control loss could alleviate these concerns. ExxonMobil is currently evaluating concepts to provide two additional methods to kill an out-of-control well. One utilizes rapid crosslinking polymers to form a polymer-plug seal inside a BOP after a failure. The other is to rapidly pump seawater into a well to produce back pressure that overpressures the entire well bore to keep hydrocarbons from escaping oil / gas bearing zones. Mixing dicyclopentadiene (DCPD) and other monomers with a ruthenium-based catalyst causes a rapid polymerization reaction that forms a high-strength, stable solid. These reactions can occur under extreme temperatures and pressures while withstanding significant contamination from other fluids and solids. The well-control concept is to rapidly pump the monomers and catalyst into a leaking BOP to form a polymer seal that prevents further flow. The seawater injection concept uses high-pressure and capacity pumps located on a surface vessel and a conduit from these pumps to a port on a BOP. If a blowout occurs, seawater at high rate is pumped in the BOP. If BOP seal failure is the reason for containment loss, then the seawater will overpressure the BOP and seawater will displace the hydrocarbons passing through the leak point. Seawater injection will also overpressure the entire wellbore to keep hydrocarbons from escaping anywhere in the well. For example, if a leak occurs deep in the well, seawater injection into the BOP will overpressure the entire well and the seawater will replace the hydrocarbon flowing through the leak point. We have conducted testing of the polymer plug concept at representative temperatures and pressures using a small-scale BOP. Polymer seals were formed when the scale BOP was flowing drilling mud, a crude-oil surrogate, and water. The seals held up to 5,000 psi pressure for almost 18 hours. We have completed modeling of the seawater injection concept to define pumping needs. This paper describes the current status of concept development.


2012 ◽  
Vol 524-527 ◽  
pp. 1628-1633
Author(s):  
Qi Ji Yuan ◽  
Zheng Zheng

During the process of drilling, overflow happens when the waterhole blocks, drilling tool breaks off and drops into the well, or empty hole occurs after hoisting completed. In course of the workover operation, overflow happens while oil tube fracturing, blocking up, and occurring empty well or can’t flow. As it is difficult to establish effective fluid cycling for such type of well when overflow occurs, conventional killing well method cannot handle the problem of overflow for the well in special operating conditions. The so-called special operating conditions well have intact well head control equipment, but unable establish cycling after the overflow well shut in. The paper is aimed at finding out the non-routine well control procedure to deal with the overflow of the well in special operating conditions. Study the well killing technology in four situations. The situation included the well is full of natural gas, lower of the well is liquid column and upper of the well is natural gas, the wellbore blocks and unable establish cycling for containing liquid column, besides the wellbore holds fish where the fish is intact and doesn’t block the wellbore, the fish blocks the wellbore or the fish is breakup and blocks the wellbore. Discuss the principles, steps, calculation procedure and formulas of killing well in volumetric control mode. The result is applied in one of the non-conventional wells’ workover operation in the eastern of Sichuan. This paper simulates the calculation of killing well and reveals the killing well curves and form design.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Xiang Zuo ◽  
Xinyuan Jiang ◽  
Pan Li ◽  
Jungang Wang ◽  
Maorong Ge ◽  
...  

AbstractReal-time satellite orbit and clock estimations are the prerequisite for Global Navigation Satellite System (GNSS) real-time precise positioning services. To meet the high-rate update requirement of satellite clock corrections, the computational efficiency is a key factor and a challenge due to the rapid development of multi-GNSS constellations. The Square Root Information Filter (SRIF) is widely used in real-time GNSS data processing thanks to its high numerical stability and computational efficiency. In real-time clock estimation, the outlier detection and elimination are critical to guarantee the precision and stability of the product but could be time-consuming. In this study, we developed a new quality control procedure including the three standard steps: i.e., detection, identification, and adaption, for real-time data processing of huge GNSS networks. Effort is made to improve the computational efficiency by optimizing the algorithm to provide only the essential information required in the processing, so that it can be applied in real-time and high-rate estimation of satellite clocks. The processing procedure is implemented in the PANDA (Positioning and Navigation Data Analyst) software package and evaluated in the operational generation of real-time GNSS orbit and clock products. We demonstrated that the new algorithm can efficiently eliminate outliers, and a clock precision of 0.06 ns, 0.24 ns, 0.06 ns, and 0.11 ns can be achieved for the GPS, GLONASS, Galileo, and BDS-2 IGSO/MEO satellites, respectively. The computation time per epoch is about 2 to 3 s depending on the number of existing outliers. Overall, the algorithm can satisfy the IGS real-time clock estimation in terms of both the computational efficiency and product quality.


Author(s):  
L. E. Murr ◽  
G. Wong

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.


Author(s):  
A. Elgsaeter ◽  
T. Espevik ◽  
G. Kopstad

The importance of a high rate of temperature decrease (“rapid freezing”) when freezing specimens for freeze-etching has long been recognized1. The two basic methods for achieving rapid freezing are: 1) dropping the specimen onto a metal surface at low temperature, 2) bringing the specimen instantaneously into thermal contact with a liquid at low temperature and subsequently maintaining a high relative velocity between the liquid and the specimen. Over the last couple of years the first method has received strong renewed interest, particularily as the result of a series of important studies by Heuser and coworkers 2,3. In this paper we will compare these two freezing methods theoretically and experimentally.


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