Using Continuous Circulation in Geothermal Wells to Improve Drilling Performance and Reduce NPT Related to Wellbore Stability

2021 ◽  
Author(s):  
Scott William Petrie ◽  
Rick Doll
Keyword(s):  
Drill Pipe ◽  
Drill String ◽  
Wellbore Stability ◽  
Circulation System ◽  
Geothermal Exploration ◽  
Drilling Performance ◽  
Rock Formations ◽  
Geothermal Wells ◽  
Fully Automatic ◽  
Productive Time

Abstract Continuous Circulation Systems (CCS) have been used in the past to help drill wells where interactions between the mud weight and theformation may increaserisks, thereby allowing the well to be drilledwithout encountering drilling problems or damaging the formation, whilst reaching total depth in the planned time. Previous systems have,however,relied on people working in the red zone. This paper discusses the process of making drill pipe connections, with continuous circulation,utilising a fully automatic deployment system to add value by removing the risk of people around the drill pipe during the connection, working in conjunction with other automated rig systems todeliver the advantages of continuously circulation over each connection. The continuous circulation subs are installed in every stand of drill pipe to be used in the drilled interval and facilitate circulation while the next stand is picked up and made up to the stump. A valve manifold is utilised to divert flow from the pumps to the subs, instead of the top drive, during the connection. During each connection, circulation is maintained down the drill string, from bit to surface, at drilling rates. Once the connection has been made the continuous circulation surface equipment is disconnected from the drill string allowing drilling to resume. After deploying the continuous circulation system on a number of geothermal projects, the results of using the system for top hole and intermediate sections suggest that while drilling with low rheology water-based mud systems,a high percentage of cuttings are returned to surface while the next stand of drill pipe is being picked up,limiting any hole loading and allowing the driller to increase the rate of penetration (ROP) through these sections. Fewer hole collapse issues were observed while drilling through volcanic tuff and ash, where wellbore stability is low due to poorly consolidated rock formations, thereby reducing non-productive time associated with stuck pipe and the costs of lost bottom hole assemblies (BHA's) and sidetracks. Most Geothermal projects work on very tight budgets and geothermal exploration costs need to be kept low. Improved drilling performance has improved the viability of these projects and increased the number of exploration wells that can be drilled in a campaign by reducing the days versus depth P90 estimate, that being the 90% probability of the rig matching the days v's depth curve predicted.

Continuous Circulation while Drilling: A New Approach to Maintain Hole Cleaning and Improve Drilling Performance in Swamp Drilling Operation

2021 ◽  
Author(s):  
B. K. Yuda
Keyword(s):  
Future Development ◽  
New Technology ◽  
Drill Pipe ◽  
Good Condition ◽  
Circulation System ◽  
Drilling Fluids ◽  
Hole Cleaning ◽  
Drilling Operation ◽  
Drilling Performance ◽  
Safety Incident

Swamp drilling operation in Mahakam has entered the industrialization period in which fast drilling is a common practice. However, fast drilling Rate of Penetration (ROP) causes hole cleaning issues to arise and induce a high Equivalent Circulating Density (ECD) trend. In some wells, this potentially leads to loss problems because of weak formation in shallow sections or depleted formation with relatively low fracture gradient. As a result, drilling parameter reduction was performed that causing lower ROP and additional circulation to reduce ECD. A new technology called Continuous Circulation Device (CCD) can help to tackle the problems mentioned above. It is a sub-based constant circulation system that enables the continuous circulation of drilling fluids downhole while making or breaking drill pipe connections. This system helps to maintain ECD and improve drilling performance as the cuttings are continuously carried out of the hole. This paper is introduced to analyze the benefits of CCD and opportunities for future development in the swamp drilling operation. The device was applied during drilling in the 12-1/4” and 8-1/2” sections. The challenge during drilling in these sections was to improve ROP without inducing bad hole cleaning that could lead to a high ECD trend. The result of CCD utilization shows that ECD during drilling could be reduced up to 2 points and become more stable compared to the previous trend. Since there was a reduction of ECD, the ROP could be improved up to 10%. Furthermore, only 1 cycle for circulation at well TD was performed as the minimum cuttings appeared. Pulling out the string and running the casing string was managed smoothly as the hole was already in a good condition. This utilization has been successfully implemented without any safety incident nor related Non-Productive Time (NPT). This positive result leads us to open the opportunity for future development in swamp fields asset.

A Rotational Continuous-Circulation Tool RCCT for Decreasing Non-Productive Time NPT and Mitigating Drilling Operational Risk

2021 ◽  
Author(s):  
Meshari Mansour Alshalan ◽  
Amjad O. Alshaarawi ◽  
Haytham H. Alhamed ◽  
Abdulwahab S. Aljohar
Keyword(s):  
Oil And Gas ◽  
Drill Pipe ◽  
Drill String ◽  
Added Value ◽  
Drilling Mud ◽  
Cleaning Efficiency ◽  
Gas Drilling ◽  
Static Contact ◽  
Continuous Rotation ◽  
Productive Time

Abstract This work presents how a Rotational Continuous-Circulation Tool (RCCT) can decrease non-productive time and mitigate risks in the oil and gas drilling operations. The proposed tool provides almost continuous rotation of the drill-string and continuous circulation of drilling mud during the making/breaking of drill-pipe connections. Continuous rotation minimizes the stationary time during the connection. Thus, the risk of static contact between the wall of the formation and drill string (which can cause a differentially stuck drill-pipe) is reduced. This is one aspect by which non-productive time (NPT) is reduced, and the potential of encountering a differentially stuck pipe incident is mitigated. Continuous circulation enhances the hole cleaning efficiency. Rather than gravitating or being suspended, drilling cuttings continue to be removed to surface during connections with continuous circulation. As a result, the risk of having a mechanical stuck pipe incident (e.g., Pack-off) is prevented. In addition, maintaining continuous circulation eliminates down-hole pressure fluctuations. This reduces the risk of hole stability issues, and also enables navigation through zones with tight drilling pressure window. The proposed tool has been trial-tested twice to demonstrate its compatibility with the current drilling rigs/practices. Further trial tests are planned to demonstrate the added value of the tool.

A Dynamic Model for Rotary Rock Drilling

1982 ◽  
Vol 104 (2) ◽  
pp. 108-120 ◽  
Author(s):  
I. E. Eronini ◽  
W. H. Somerton ◽  
D. M. Auslander
Keyword(s):  
Drill Pipe ◽  
Tooth Wear ◽  
Drill String ◽  
Rock Drilling ◽  
Large Power ◽  
Drilling Rig ◽  
Drilling Performance ◽  
Weight On Bit ◽  
Rotary Speed ◽  
Mud Pressure

A rock drilling model is developed as a set of ordinary differential equations describing discrete segments of the drilling rig, including the bit and the rock. The end segment consists of a description of the bit as a “nonideal” transformer and a characterization of the rock behavior. The effects on rock drilling of bottom hole cleaning, drill string-borehole interaction, and tooth wear are represented in the model. Simulated drilling under various conditions, using this model, gave results which are similar to those found in field and laboratory drilling performance data. In particular, the model predicts the expected relationships between drilling rate and the quantities, weight on bit, differential mud pressure, and rotary speed. The results also suggest that the damping of the longitudinal vibrations of the drill string could be predominantly hydrodynamic as opposed to viscous. Pulsations in the mud flow are found to introduce “percussive” effects in the bit forces which seem to improve the penetration rate. However, it is known from field observations that drill pipe movements, if strong enough, may induce mud pressure surges which can cause borehole and circulation problems. Bit forces and torques are shown to be substantially coupled and the influence of certain rock parameters on variables which are measurable either at the bit or on the surface support the expectation that these signals can furnish useful data on the formation being drilled. Other results, though preliminary, show that the effects of the lateral deflections of the drill string may be large for the axial bit forces and significant for the torsional vibrations. For the latter, the unsteady nature of the rotation above the bit increases and the resistance to rotation due to rubbing contact between the drill string and the wellbore accounts for very large power losses between the surface and the bit.

Drilling System Optimization Leads to Expedited Wells Delivery

2021 ◽  
Author(s):  
Efe Mulumba Ovwigho ◽  
Saleh Al Marri ◽  
Abdulaziz Al Hajri
Keyword(s):  
Drill Pipe ◽  
System Optimization ◽  
Drill String ◽  
Stick Slip ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Single String ◽  
Innovative Solution ◽  
Open Hole ◽  
Weight On Bit

Abstract On a Deep Gas Project in the Middle East, it is required to drill 3500 ft of 8-3/8" deviated section and land the well across highly interbedded and abrasive sandstone formations with compressive strength of 15 - 35 kpsi. While drilling this section, the drill string was constantly stalling and as such could not optimize drilling parameters. Due to the resulting low ROP, it was necessary to optimize the Drill string in order to enhance performance. Performed dynamic BHA modelling which showed current drill string was not optimized for drilling long curved sections. Simulation showed high buckling levels across the 4" drill pipe and not all the weight applied on surface was transmitted to the bit. The drilling torque, flowrate and standpipe pressures were limited by the 4" drill pipe. This impacted the ROP and overall drilling performance. Proposed to replace the 4" drill pipe with 5-1/2" drill pipe. Ran the simulations and the model predicted improved drill string stability, better transmission of weights to the bit and increased ROP. One well was assigned for the implementation. Ran the optimized BHA solution, able to apply the maximum surface weight on bit recommended by the bit manufacturer, while drilling did not observe string stalling or erratic torque. There was also low levels of shocks and vibrations and stick-slip. Doubled the on-bottom ROP while drilling this section with the same bit. Unlike wells drilled with the previous BHA, on this run, observed high BHA stability while drilling, hole was in great shape while POOH to the shoe after drilling the section, there were no tight spots recorded while tripping and this resulted in the elimination of the planned wiper trip. Decision taken to perform open hole logging operation on cable and subsequently run 7-in liner without performing a reaming trip. This BHA has been adopted on the Project and subsequent wells drilled with this single string showed similar performance. This solution has led to average savings of approximately 120 hours per well drilled subsequently on this field. This consist of 80 hours due to improved ROP, 10 hrs due to the elimination of wiper trip and a further 30 hrs from optimized logging operation on cable. In addition, wells are now delivered earlier due to this innovative solution. This paper will show how simple changes in drill string design can lead to huge savings in this current climate where there is a constant push for reduction in well times, well costs and improved well delivery. It will explain the step-by-step process that was followed prior to implementing this innovative solution.

scholarly journals The Effect of Invisible Lost Time on Drilling Performance of Geothermal Wells

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Fernandez Sabar Hasudungan Pangaribuan ◽  
Sugiatmo Kasmungin ◽  
Suryo Prakoso
Keyword(s):  
Performance Indicator ◽  
Night Shift ◽  
Drilling Performance ◽  
Open Hole ◽  
Geothermal Wells ◽  
Lost Time ◽  
Geothermal Drilling ◽  
The Cost ◽  
Productive Time ◽  
Better Than

<em>Drilling activity has been focused in time on each activity to reach target depth (TD) immediately and efficient in cost. The priority also aimed to Geothermal drilling by doing specific measurement on Invisible Lost Time (ILT) as new focus to perform. Time becomes main aspect which it would affect the cost, therefore it is important to complete the well in time manner. The research was done to analyze the offset well of well A, B, C and D in order to identify Productive Time and Non Productive Time. Key Performance Indicator (KPI) has been identified from each activity also targeted from two wells of well B dan Well D due to time efficiency used during operation. The method used by comparing offset wells then continue to identify each KPI by measuring each activity based on ASCII time and Daily Drilling Report (DDR). The result from offset wells showed inefficiency in time with Flat time 49%, Drilling 42% and non-flat time (NPT) 9% from 28 days without completion. KPI based on the crew performance has confirmed that day shift crew performed better than night shift crew. KPI on rate of penetration (ROP) on day shift crew at 6 m/hr and night crew at 3 m/hr. KPI on Weight to Weight on day shift crew at 28.43 minute/stand faster than night shif crew at 34.65 minute/stand. KPI on Tripping in cased hole on day shift crew at 4.5 minute/stand faster than night crew shift at 4.6 minute/stand. KPI on Tripping in open hole on day shift crew at 2.7 minute/stand faster than night shift crew at 3.7 minute/stand. KPI on Tripping out open hole on day shift crew at 3.0 minute/stand slower than night shift crew at 2.8 minute/stand. KPI on Tripping out cased hole on day shift crew at 3.36 minute/stand faster than night crew shift at 3.74 minute/stand. ILT from both wells to 20 % or 5 days inefficiency on each well. It detects of potential savings to 10 billion rupiah from both wells.</em>

Simulation of Drill Pipe Lateral Vibration due to Riser's Oscillation

2013 ◽  
Vol 845 ◽  
pp. 168-172
Author(s):  
Nabil Al Batati ◽  
Fakhruldin M. Hashim ◽  
William Pao
Keyword(s):  
Drill Pipe ◽  
Low Frequency ◽  
Major Effect ◽  
Drill String ◽  
Drilling Process ◽  
Marine Riser ◽  
Maximum Displacement ◽  
Drilling Performance ◽  
Drilling Tools ◽  
Negative Damping

This paper attempts to explain the motion behaviour of the marine riser coupled to a drill string when the vortex induced vibration (VIV) is involved. Vibrations have been reported to have a major effect on the drilling performance, affecting the rate of penetration (ROP), causing severe damages to the drilling tools and also reduces the efficiency of the drilling process. There are two major components of drilling tools that are subjected to vibration, namely the marine riser and the drilling string. Analysis of vibration in the marine riser and drill string are two topical areas that have individually received considerable attention by researchers in the past. Though these two subjects are interrelated, borne by the fact that the marine riser encapsulates and protects the drill pipe, there have been few attempts to investigate them together as a unity. Due to the complexities of the models, simplified assumptions were made in order to undertake the investigation by using staggered approach. The results were compared with the experimental and simulation data from the open literature. It was found that the maximum displacement with negative damping occurs at low frequency and rotation speed.

scholarly journals Analytical Study of Early Kick Detection and Well Control Considerations for Casing while Drilling Technology

2021 ◽  
Author(s):  
M Azab
Keyword(s):  
Drill Pipe ◽  
Drill String ◽  
Wellbore Stability ◽  
Well Control ◽  
Lost Circulation ◽  
Drilling Technique ◽  
Drilling Technology ◽  
Drilling Operations ◽  
Fracture Gradient ◽  
Conventional Drilling

Abstract Recently, casing while drilling (CwD) technology has been employed to reduce drilling time and expenses. These intelligent drilling technique improved wellbore stability, fracture gradient, and formation damage while reducing exposure time but when a well control issue arises, the differences in wellbore geometries and related volumes compared to regular conventional drilling procedures necessitate a distinct strategy. In this paper, the essential well control parameters were provided for casing while drilling operations, presents simplified method that has been developed to evaluate the maximum kick tolerance (KT) for both conventional and casing while drilling techniques using a mathematical derivation, the narrow annular clearance, in contrast to drilling with a conventional drill string would impair kick detection and handling operations. Furthermore, the large disparity in kick tolerances should be carefully evaluated in order to avoid lost circulation/kick cycles as well as examine and evaluate technical approaches to early kick detection (EKD) studying how they relate to safety, efficiency, and reliability in a variety of common casing while drilling operations. According to preliminary findings, by utilizing casing while drilling technology and compared to identical well was drilled conventionally using drill pipe, the annulus pressure loss (APL) is average 3 times of the conventional drilling technique. Furthermore, kick tolerance is reduced by 50% and maximum allowable well shut-in time reduced by 65% necessitating early kick detection.

Anti-Flushing Design for Continuous Circulation System

2010 ◽  
Vol 160-162 ◽  
pp. 768-772
Author(s):  
Ding Feng ◽  
Liu Li ◽  
Hai Xiong Tang
Keyword(s):  
Drill String ◽  
Wellbore Stability ◽  
Small Hole ◽  
Pressure Increase ◽  
Circulation System ◽  
Pressure Management ◽  
Well Drilling ◽  
Critical Part ◽  
Wellbore Pressure

Proper wellbore pressure management is a critical part of the drilling practice, where static and dynamic fluid pressures are used to contain formation pressures and assure wellbore stability, to solve the problem; the anti-flushing device is has been developed. The anti-flushing device is designed to counter downhole pressure increase due to safety of narrow mud window and the key to fast drilling. Reasonable control anti-flushing device is the best way to solve the safety of narrow mud window and the key to fast drilling. This paper describes the anti-flushing device, which is run as an integral part of the drill string. The anti-flushing device has been built to operate the 8-1/2 "section of well drilling, keeping continuous loop, To avoiding annular cutting is sank into accumulation when the drill string were connected and the pump stopped, cleaning the small hole by maximum.

Applications of Nanomaterials in Wellbore Fluids in Oil and Gas Fields

2021 ◽  
Vol 881 ◽  
pp. 33-37
Author(s):  
Wei Na Di
Keyword(s):  
Oil And Gas ◽  
Drill String ◽  
Wellbore Stability ◽  
Petroleum Engineering ◽  
Cement Stone ◽  
Drilling Fluids ◽  
Cement Slurry ◽  
Oil And Gas Fields ◽  
Gas Channeling ◽  
Gas Fields

The application of nanomaterials in oil and gas fields development has solved many problems and pushed forward the development of petroleum engineering technology. Nanomaterials have also been used in wellbore fluids. Nanomaterials with special properties can play an important role in improving the strength and flexibility of mud cake, reducing friction between the drill string and wellbore and maintaining wellbore stability. Adding nanomaterials into the cement slurry can eliminate gas channeling through excellent zonal isolation and improve the cementing strength of cement stone, thereby facilitating the protection and discovery of reservoirs and enhancing the oil and gas recovery. This paper tracks the application progress of nanomaterials in wellbore fluids in oil and gas fields in recent years, including drilling fluids, cement slurries. Through the tracking and analysis of this paper, it is concluded that the applications of nanomaterials in wellbore fluids in oil and gas fields show a huge potential and can improve the performance of wellbore fluids.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure

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