Systematic Build-Up Pressure Analysis Advances Accurate Fingerprinting of Formation Breathing in Gas Wells

2021 ◽  
Author(s):  
Maria Retuta ◽  
Leiro Medina
Keyword(s):  
False Negative ◽  
Gas Wells ◽  
Deep Basin ◽  
Well Control ◽  
Control Procedures ◽  
Drilling Parameter ◽  
Time Savings ◽  
Will Force ◽  
Drilling Time ◽  
Productive Time

Abstract Differentiating wellbore breathing from real influxes in Alberta's Deep Basin has been problematic in the past as they both result in similar surface parameters. An incorrect interpretation of formation breathing may lead to significant non-productive time (NPT) as secondary well control operations from an influx can take days. On the contrary, a false negative will force drillers to perform secondary well control procedures that may lead to loss of circulation if excessive and unnecessary pressure is exerted on the formation. MPD allows for a systematic approach to identify wellbore breathing more accurately in gas wells. The process involves a series of consecutive pressure build-up and flowback tests with close real-time monitoring to identify a breathing formation that is returning fluid to surface as microfractures close. This paper describes the protocol designed for distinguishing wellbore breathing and illustrates how several drilling parameter trends were interpreted to correctly identify wellbore breathing characteristics and differentiate them from a migrating gas influx. Testing the procedure on multiple wells resulted in 70% operational time savings from reduction in post mud rollover delays on breathing wellbores. This paper shows that the methodology utilized provides consistent and effective results using the MPD techniques, eliminates the ambiguity of wellbore breathing versus actual influxes, and shows the potential application in more areas that are prone to this problem, reducing uncertainty, NPT, and total drilling time.

Bottom Hole Assembly Design Enhancement Successfully Eliminate Hole Problems and Reduce Significant Drilling Time : South S Field Case Study

2020 ◽  
Author(s):  
Y. D. Mulia
Keyword(s):  
Contact Area ◽  
Cost Savings ◽  
Assembly Design ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Unconsolidated Sand ◽  
Bottom Hole Assembly ◽  
Drilling Parameter ◽  
Drilling Time

For S-15 and S-14 wells at South S Field, drilling of the 12-1/4” hole section became the longest tangent hole section interval of both wells. There were several challenges identified where hole problems can occur. The hole problems often occur in the unconsolidated sand layers and porous limestone formation sections of the hole during tripping in/out operations. Most of the hole problems are closely related to the design of the Bottom Hole Assembly (BHA). In many instances, hole problems resulted in significant additional drilling time. As an effort to resolve this issue, a new BHA setup was then designed to enhance the BHA drilling performance and eventually eliminate hole problems while drilling. The basic idea of the enhanced BHA is to provide more annulus clearance and limber BHA. The purpose is to reduce the Equivalent Circulating Density (ECD,) less contact area with formation, and reduce packoff risk while drilling through an unconsolidated section of the rocks. Engineering simulations were conducted to ensure that the enhanced BHA were able to deliver a good drilling performance. As a results, improved drilling performance can be seen on S-14 well which applied the enhanced BHA design. The enhanced BHA was able to drill the 12-1/4” tangent hole section to total depth (TD) with certain drilling parameter. Hole problems were no longer an issue during tripping out/in operation. This improvement led to significant rig time and cost savings of intermediate hole section drilling compared to S-15 well. The new enhanced BHA design has become one of the company’s benchmarks for drilling directional wells in South S Field.

Utilizing Novel Expandable Steel Packers to Overcome Multi-Stage Fracturing Completion Deployment Challenges in Horizontal Gas Wells

2021 ◽  
Author(s):  
Ebikebena M. Ombe ◽  
Ernesto G. Gomez ◽  
Aldia Syamsudhuha ◽  
Abdullah M. AlKwiter
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Cost Effective ◽  
Outer Diameter ◽  
Gas Wells ◽  
Multi Stage ◽  
High Pressure High Temperature ◽  
Zonal Isolation ◽  
Gas Bearing ◽  
Productive Time

Abstract This paper discusses the successful deployment of Multi-stage Fracturing (MSF) completions, composed of novel expandable steel packers, in high pressure, high temperature (HP/HT) horizontal gas wells. The 5-7/8" horizontal sections of these wells were drilled in high pressure, high temperature gas bearing formations. There were also washed-outs & high "dog-legs" along their wellbores, due to constant geo-steering required to keep the laterals within the hydrocarbon bearing zones. These factors introduced challenges to deploying the conventional MSF completion in these laterals. Due to the delicate nature of their packer elastomers and their susceptibility to degradation at high temperature, these conventional MSF completions could not be run in such hostile down-hole conditions without the risk of damage or getting stuck off-bottom. This paper describes the deployment of a novel expandable steel packer MSF completion in these tough down-hole conditions. These expandable steel packers could overcome the challenges mentioned above due to the following unique features: High temperature durability. Enhanced ruggedness which gave them the ability to be rotated & reciprocated during without risk of damage. Reduced packer outer diameter (OD) of 5.500" as compared to the 5.625" OD of conventional elastomer MSF packers. Enhanced flexibility which enabled them to be deployed in wellbores with high dog-leg severity (DLS). With the ability to rotate & reciprocate them while running-in-hole (RIH), coupled with their higher annular clearance & tolerance of high temperature, the expandable steel packers were key to overcoming the risk of damaging or getting stuck with the MSF completion while RIH. Also, due to the higher setting pressure of the expandable steel packers when compared to conventional elastomer packers, there was a reduced risk of prematurely setting the packers if high circulating pressure were encountered during deployment. Another notable advantage of these expandable packers is that they provided an optimization opportunity to reduce the number of packers required in the MSF completion. In a conventional MSF completion, two elastomer packers are usually required to ensure optimum zonal isolation between each MSF stage. However, due to their superior sealing capability, only one expandable steel packer is required to ensure good inter-stage isolation. This greatly reduces the number of packers required in the MSF completion, thereby reducing its stiffness & ultimately reducing the probability of getting stuck while RIH. The results of using these expandable steel packers is the successful deployment of the MSF completions in these harsh down-hole conditions, elimination of non-productive time associated with stuck or damaged MSF completion as well as the safe & cost-effective completion in these critical horizontal gas wells.

Comparative Study of Managed Pressure Drilling Application in Deepwater Gas Wells - Case Study from Offshore Eastern Mediterranean of Egypt

2021 ◽  
Author(s):  
Mahmoud Ahmed El-Husseiny ◽  
Samir Mohamed Khaled ◽  
Taher El-Sebaay El-Fakharany ◽  
Yehia Mohamed Al-Nadi
Keyword(s):  
Comparative Study ◽  
Detection System ◽  
Eastern Mediterranean ◽  
Gas Wells ◽  
Gas Field ◽  
Well Control ◽  
Rate Of Penetration ◽  
Drilling Performance ◽  
Managed Pressure Drilling ◽  
Conventional Drilling

Abstract Although devised in 2003, managed pressure drilling (MPD) has gained widespread popularity in recent years to precisely control the annular pressure profile throughout the wellbore. Due to the relatively high cost and complexity of implementing MPD, some operators still face a challenge deciding whether or not to MPD the well. In the offshore Mediterranean of Egypt, severe to catastrophic mud losses are encountered while conventionally drilling deepwater wells through cavernous fractured carbonate gas reservoirs with a narrow pore pressure-fracture gradient (PP-FG) window, leading to the risk of not reaching the planned target depth (TD). Furthermore, treating such losses was associated with long non-productive time (NPT), massive volume consumption of cement, and lost-circulation materials (LCM), in addition to well control situations encountered several times due to loss of hydrostatic head during severe losses. Accordingly, the operator decided to abandon the conventional drilling method and implement MPD technology to drill these problematic formations. In this paper, the application of MPD is to be examined versus the conventional drilling in terms of well control events, NPT, rate of penetration (ROP), mud losses per drilled meter, LCM volume pumped, and drilling operations optimization. According to the comparative study, MPD application showed a drastic improvement in all drilling performance aspects over the conventional drilling where the mud losses per drilled meter reduced from 19.6 m3/m to 3.7m3/m (123.2 bbl/m to 23.4 bbl/m). In addition to that, a 35% reduction of NPT and also a 35% reduction of LCM pumped, and 67.2 % reduction by volume of cement pumped to cure the mud losses. Moreover, the average mechanical rate of penetration increased by 37.4%. MPD was also credited with eliminating the need for an additional contingent 7" liner which was conventionally used to isolate the thief zone. The MPD ability to precisely control bottom hole pressure during drilling with the integration of MPD early kick detection system enables the rapid response in case of mud loss or kick, eliminating kick-loss cycles, well control events, and drilling flat time to change mud density. This paper provides an advanced and in-depth study for deep-water drilling problems of a natural gas field in the East Mediterranean and presents a comprehensive analysis of the MPD application with a drilling performance assessment (average ROP, mud losses, LCM and cement volumes, well control events) emphasizing how MPD can offer a practical solution for future drilling of challenging deepwater gas wells.

Study on Influx Risk Evaluation of Horizontal Gas Wells With High-Pressure High-Temperature in the South China Sea

2020 ◽  
Author(s):  
Ming Luo ◽  
Deli Gao ◽  
Xin Zhao ◽  
Yuan Chen ◽  
Yupeng Yang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
South China Sea ◽  
Risk Evaluation ◽  
Control Strategies ◽  
Control Design ◽  
Gas Wells ◽  
Well Control ◽  
High Pressure High Temperature ◽  
Open Hole

Abstract The South China Sea has rich natural gas source with typical high-pressure high-temperature (HPHT) and the extremely narrow drilling window, which leads to frequent influx, even borehole abandonment. However, horizontal gas wells have been placed in the area to develop the gas reservoir, which presents greater well control challenges. Therefore, the influx risk evaluation is quite necessary to guide the well control design. Firstly, the influx mechanism is analyzed based on gas intrusion to provide a theoretical basis for well control design. It is found that influx usually occurs when drilling the high-temperature stratums and target layers. Secondly, the relationship between horizontal open-hole length and influx volume is calculated under different reservoir permeability, reservoir thickness, negative bottom hole pressure and horizontal open-hole section length. Thirdly, the characteristics of gas-liquid two-phase flow are described. Fourthly, the inflow risk evaluation and well control strategies of the target horizontal gas wells are proposed, and the influx risk evaluation envelope was established. The influx risk evaluation and well control strategies have been successfully applied to the DF gas field featuring offshore HPHT. Horizontal gas wells were drilled in the micro pressure window without accidents and the well cost was significantly reduced.

MANAGEMENT OF THE UNIACKE G-72 INCIDENT

1985 ◽  
Vol 1985 (1) ◽  
pp. 311-313 ◽  
Author(s):  
S. D. Gill ◽  
C. A. Bonke ◽  
J. Carter
Keyword(s):  
Monitoring Program ◽  
Chemical Properties ◽  
Well Being ◽  
Gas Well ◽  
Well Control ◽  
Drilling Rig ◽  
Sampling Program ◽  
Control Procedures ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACT During the evening of February 22, 1984, the Uniacke G-72 gas well being drilled 150 nautical miles off Halifax, Nova Scotia, by the semisubmersible drilling rig, Vinland, under contract to Shell Canada Resources, blew out of control, emitting gas and condensate at an estimated rate of 300 bbl per day. During the following 10 days while Shell was assembling personnel, vessels, and equipment for reboarding the rig and initiating well control procedures, a comprehensive environmental monitoring program was put in place. An air, slick, and water column sampling program was initiated to provide information on the physical and chemical properties of the condensate. This paper describes the primary findings of the program that involved the coordination of government, area petroleum operators, and consultants.

Well Control Procedures for Dual Gradient Drilling as Compared to Conventional Riser Drilling

2006 ◽  
Vol 21 (04) ◽  
pp. 287-295 ◽  
Author(s):  
Jerome J. Schubert ◽  
Hans C. Juvkam-Wold ◽  
Jonggeun Choe
Keyword(s):  
Well Control ◽  
Control Procedures ◽  
Dual Gradient

scholarly journals Building 1D Mechanical Earth Model for Zubair Oilfield in Iraq

2020 ◽  
Vol 26 (5) ◽  
pp. 47-63
Author(s):  
Aows Khalid Neeamy ◽  
Nada Sabah Selman
Keyword(s):  
Earth Model ◽  
Drilling Process ◽  
Suitable Alternative ◽  
Wellbore Instability ◽  
Drilling Operations ◽  
Mechanical Earth Model ◽  
Alternative Solutions ◽  
Drilling Time ◽  
Productive Time ◽  
Critical Limits

Many problems were encountered during the drilling operations in Zubair oilfield. Stuckpipe, wellbore instability, breakouts and washouts, which increased the critical limits problems, were observed in many wells in this field, therefore an extra non-productive time added to the total drilling time, which will lead to an extra cost spent. A 1D Mechanical Earth Model (1D MEM) was built to suggest many solutions to such types of problems. An overpressured zone is noticed and an alternative mud weigh window is predicted depending on the results of the 1D MEM. Results of this study are diagnosed and wellbore instability problems are predicted in an efficient way using the 1D MEM. Suitable alternative solutions are presented ahead to the drilling process commences in the future operations.

scholarly journals Casing while Drilling – a Viable Alternative to Conventional Drilling

2019 ◽  
Vol 290 ◽  
pp. 10003
Author(s):  
Ion Foidaş ◽  
Dan-Paul Ștefănescu ◽  
Mihai Serbancea
Keyword(s):  
New Technologies ◽  
Drilling Fluid ◽  
Mechanical Energy ◽  
Viable Alternative ◽  
Drilling Process ◽  
Drilling Depth ◽  
Drilling String ◽  
Drilling Time ◽  
Productive Time ◽  
Conventional Drilling

Mankind’s increased requirement for and dependence on energy resources, including the resources resulting from discovery and development of new hydrocarbon commercial reservoirs involves the use of new technologies such as optimization of the drilling process by reducing the non-productive time, the costs and the risks. Casing while drilling involves elimination of classical drilling string by using the casing string both for transmission to the bit of the mechanical energy and for circulation of drilling fluid into the well. Although there is a number of technical or perception barriers related to the use of casing drilling, the important benefits of this technology related to reduced drilling time and problems associated to the drilling string make it an increasingly viable alternative to conventional drilling. The experience in applying this technology has proven that it can reduce the time of well execution and sometimes it lowers the costs in relation to drilling depth.

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