Making Workovers Easy and Cost Effective: Turning Old Ways into New Opportunities

2021 ◽  
Author(s):  
Mustansar Raza ◽  
Hossam Elmoneim ◽  
Kris Looten ◽  
Omar Elzanaty ◽  
Ahmed Shakeel ◽  
...  

Abstract A case study and methodology is presented to shed the light on the different processes followed during the placement of a non-damaging isolation barrier in a group of highly naturally-fractured and vugular gas wells. The temporary isolation aims at isolating the wellbore from the troublesome formation and allow the removal of the original completion string and install a new redesigned one. The process helped putting the wells back on production with-out the need to stimulate any of them. This helped client to reduce the overall workover cost by 40% and proved to be successful and efficient to complete the required operation in a time-efficient. The operator had 4 wells with OH sections ranging from 40-80m which were completed in the late 1990's with no production packer. To preserve wellbore integrity the completion string needed to be pulled and replaced by a string with production packer and DH gauges. Visco-Elastic Surfactant (VES) and calcium CaCO3 (carbonate) used ubiquitously in field operations were tested for optimal design to fill highly fractured OH without damaging formation. Caliper logs were not available, and the presence of natural fractures posed a challenge to calculate the actual OH volume. A system was developed to carry the CaCO3 into the wellbore in stages and slickline was employed to measure fill after each stage. Once the OH was filled with CaCO3 and well would support a fluid column coil tubing was used to place an acid-soluble cement plug in the short interval between casing shoe and end of tubing (6-9m). The paper describes the optimization process followed to tune the CaCO3 pads composition, gel composition, mixing and placement technique. The first well in the campaign required more than 10 times the theoretical volume of CaCO3 to fill the open hole with multiple settling issues at surface. It was concluded the surfactant gel was likely carrying the CaCO3 into the fractures. The procedure was modified to tie in a line of breaker solution to the well head allowing sufficient viscosity of the fluid to carry the CaCO3 from surface but immediately lose viscosity and allow the CaCO3 to settle in the open hole without being carried into the formation. Specific coil tubing procedures were employed to allow the setting of ultra-short acid soluble cement plugs (<6m). All wells were successfully isolated to allow the safe workover of the completion string and returned to production with no loss of gas flow, with-out the need to stimulate after the work over. The campaign exhibited a new method of employing existing technologies to achieve the objective in a highly challenging and relatively new oilfield of Kurdistan. The campaign also demonstrated the benefit, in terms of saving time and cost because of extensive pre-execution planning.

2021 ◽  
Author(s):  
Kristopher A Looten ◽  
Mustansar Raza

Abstract Objectives/Scope A case study is presented detailing the methodology used to place a non-damaging temporary isolation barrier in a group of naturally fractured, prolific gas wells in a field in Kurdistan. The temporary isolation facilitated removal of the original completion string and installation of the redesign. Wells were returned to production with-out the need to stimulate proving success of the non-damaging methodology employed. Methods, Procedures, Process The operator had 4 wells with OH sections ranging from 33-181m which were completed in the 1980’s - 1990's with no production packer. In order to preserve well bore integrity the completion string needed to be pulled and replaced by a string with production packer and DH gauges. A procedure was developed to fill the highly fractured OH with a mixed particle size CaCO3 carried into the wellbore by a non-damaging surfactant based gel. Caliper logs were not available and the presence of natural fractures posed a challenge to calculating the actual OH volume. A system was developed to carry the CaCO3 into the wellbore in stages and slickline was employed to measure fill after each stage. Once the OH was filled with CaCO3 and well would support a fluid column coil tubing was used to place an acid soluble cement plug in the short interval between casing shoe and end of tubing (8-10m) Results, Observations, Conclusions The first well in the campaign required more than 10 times the theoretical volume of CaCO3 to fill the open hole. It was concluded the surfactant gel was likely carrying the CaCO3 into the fractures. The procedure was modified to tie in a line of breaker solution to the well head allowing sufficient viscosity of the fluid to carry the CaCO3 from surface but immediately lose viscosity and allow the CaCO3 to settle in the wellbore without being carried into the formation. Specific coil tubing procedures were employed to allow the setting of ultra-short acid soluble cement plugs (<10m). All wells were successfully isolated to allow the safe workover of the completion string and returned to production with no loss of gas flow, with-out the need to stimulate after the work over. Novel/Additive Information The campaign exhibited a new method of employing existing technologies to achieve the objective in a highly challenging and relatively new oilfield of Kurdistan. The campaign also demonstrated the benefit of the operator and service company closely collaborating on each step of a novel process. The workovers would not have been successful with-out the close collaboration of the two companies.


2011 ◽  
Author(s):  
Norhisham Safiin ◽  
Abdo Ahmad ◽  
Nik Zarina Suryana Nik Khansani ◽  
Norlin Muhammad Ghazali ◽  
Osman Zainal Abidin ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Barzan Ahmed ◽  
Farhad Abdulrahman Khoshnaw ◽  
Mustansar Raza ◽  
Hossam Elmoneim ◽  
Kamil Shehzad ◽  
...  

Abstract A case study is presented detailing the methodology used to perform the clean-out operation in a water disposal well of Khurmala Field, Kurdistan Region of Iraq. Untreated disposed water caused scaling and plugging in perforated liner and in the open hole that eventually ceased injection. Multiple attempts and investments were made in recent years to resume access to the injection zone using high-pressure hydro-jetting tools coupled with acid treatments. However, these attempts yielded futile efforts. Before proceeding with the decision of workover, it was decided to go for one final attempt to regain wellbore access using Fluidic Oscillator (SFO). Fluidic Oscillator (SFO) having pulsing, cavitation and helix jetting action was used in combination with a train of fluids consisting of diesel, 28% HCl and gel. The clean out was performed in stages of 10m, to clean the fill from 1091m to 1170m. Since the well bore was initially isolated from the injection zone, the cleanout was conducted with non-nitrified fluids. As the cleanout progressed and access to the liner and open hole was regained, the circulation of insoluble fill to surface required a lighter carrying fluid. Nitrification, volume of the fluids, batch cycling, and ROP were designed considering the downhole dynamic changes expected during each stage of the operation. The combination of SFO, the thorough selection of treatment fluids and the accurate downhole hydraulics simulations pertaining to different stages of the operation offered an effective solution and regained the connectivity between the wellbore and the injection zone. The injection rate of water increased from 0 bpm at 700 psi to 15 bpm at 200 psi. Throughout this operation, the SFO helix, cavitation, and acoustic pulse (alike) jetting proved to be more effective than other single acting rotating jetting tools. Also, Environmental impact was reduced by eliminating the need for a rig workover operation. The matching of the injection pressure when the well was first completed and the post job value indicated that the complete zone was exposed and scale deposits were removed from the critical matrix or bypassed. SFO has an effective jetting near wellbore region, while the kinetic energy transferred via fluid makes the impact stronger in the deeper region. Internal mechanism of the tool allows it to handle high pumping rate and pressures, external finishing offer multi-port orientation of outflow that allows targeting the fill in desired directions. Presently the SFO used in the case study is the only technology that has pulse, cavitation, and helix jetting structure. Also, since the tool does not require redressing, it proves to be an efficient, safe and cost effective alternative


2021 ◽  
Author(s):  
Naser Al-Barazi ◽  
Faisal Adel Al-Naqa ◽  
Manoj Chouhan ◽  
Alanoud Mahdi Al-Mekhlef ◽  
Ashraf Mohammad Saleh ◽  
...  

Abstract This article presents a unique case study where operating company, Kuwait Oil Company (KOC), decided to make an attempt to perform open hole side-track through a very narrow side-track window along with other exiting conditions such as severe downhole losses and drill through very challenging formation. To deliver such project in first attempt requires very detailed planning, close coordination with various service partners such as directional drilling and cementing. Placing a good side-track cement plug in such formation was a challenge, and 2nd challenge to get kicked off from this narrow window in first attempt which was the key. In case of failure, whip stock option has to be planned as a contingency, which possess new challenging of opening a depleted zone leading to commingling low/high pressure formation which could cause a complicated problem such as borehole stability, leads to stuck pipe problem. Failure to side-track from open hole could end of planning to drill extra hole which required extra casing string to run which will put this project well over AFE and heavily impact on well objective. This open hole Side-track was planned because while drilling original hole (12 ¼" hole section) close to planned well TD, experienced complete losses. In attempt to cure the losses, LCM was pumped with no success. Performed thixotropic cement plug job for losses control. While performing thixotropic cement plug job, the cement flash set before finishing the displacement, leading to stuck string. After backing off string and fishing attempts, unable to recover the fish completely. Fish left in hole leading to only 68 ft of open hole window available to side-track where performing a cement job was impossible due to severe losses. Only way to secure the well is to try for open hole side-track. With existing sever loss situation for initiating open hole side-track was a serious challenge due to lack of side force and flow restriction to initiate the side-track. Extensive pre-job planning, peer review and risk assessment was done in coordination with various service partners to deliver such challenging side-track. A hazard analysis decision tree was established to pinpoint the risks and appropriate mitigation measures along with contingency plan put in place. A detailed side-track guidelines was shared and review with the field crew. The wellbore was successfully side-tracked through a challenging reactive shale formation in a first attempt using a customized kick-off BHA, which not only helped to avoid loss zone in side-tracked hole but also provide additional cost savings to the company. The good hole condition at the side-track point was important to enable smooth passing of the following directional BHA to achieve directional goals.


Author(s):  
B. Biondi

Regulation PTK-040 SKK MIGAS explained that the oil company must permanently close the wells post-production operations. Cluster-X has complex well conditions, so the observation needs to be cost-effective. The observation on this case refers to SNI 13-6910-2002 explaining the permanent abandonment of wells in the isolation of open-hole zones, perforation zones, blockage of casing stub (junk) as Primary well-barrier and the annular space blockage as a Secondary well-barrier. The next stage is the surface plug as an environmental isolation plug. API BUL E3-FIRST EDITION & NORSOK STANDARD D-010 are also needed for permanent abandonment on surface capping and slotted-liners in multiple reservoirs. Additional references such as API-Spec-10A are needed. The final stage is the testing of cement plugs, hole cleaning process, and budgeting. This paper discusses various conditions of wells on Cluster-X such as abnormally high pressure, cement plug with open-hole slotted-liners in multiple reservoirs, and junk left in-hole. The first step was to run with a balance plug method on ± 10,500-10,971 ft MD as Primary well-barrier. The next step was to run a cement squeeze method with bridge plug on ±7200-7500 ft MD as Secondary well-barrier. On the step of environmental isolation plug a cement plug retainer was run as a weight test with 15,000 pounds the same on previous steps. Type G class cement was selected to cement plug and ran off section milling tools above of the overpressure zone. The wells closure method compares between rigless method coiled tubing unit and portable rig (conventional) which can optimize plug & abandonment operating time and operational cost.


2012 ◽  
Vol 17 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Krzysztof Strzecha ◽  
Tomasz Koszmider ◽  
Damian Zarębski ◽  
Wojciech Łobodziński

Abstract In this paper, a case-study of the auto-focus algorithm for correcting image distortions caused by gas flow in high-temperature measurements of surface phenomena is presented. This article shows results of proposed algorithm and methods for increasing its accuracy.


2021 ◽  
pp. 0308518X2110266
Author(s):  
Neil Argent ◽  
Sean Markey ◽  
Greg Halseth ◽  
Laura Ryser ◽  
Fiona Haslam-McKenzie

This paper is concerned with the socio-spatial and ethical politics of redistribution, specifically the allocation of natural resources rents from political and economic cores to the economic and geographical peripheries whence the resource originated. Based on a case study of the coal seam gas sector in Queensland's Surat Basin, this paper focuses on the operation of the Queensland State Government's regional development fund for mining and energy extraction-affected regions. Employing an environmental justice framework, we critically explore the operation of these funds in ostensibly helping constituent communities in becoming resilient to the worst effects of the ‘staples trap’. Drawing on secondary demographic and housing data for the region, as well as primary information collected from key respondents from mid-2018 to early 2019, we show that funds were distributed across all of the local government areas, and allocated to projects and places primarily on a perceived economic needs basis. However, concerns were raised with the probity of the funds’ administration. In terms of recognition justice, the participation of smaller and more remote towns and local Indigenous communities was hampered by their structural marginalisation. Procedurally, the funds were criticised for the lack of local consultation taken in the development and approval of projects. While spatially concentrated expenditure may be the most cost-effective use of public monies, we argue that grant application processes should be open, transparent and inclusive, and the outcomes cognisant of the developmental needs of smaller communities, together with the need to foster regional solidarity and coherence.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1886
Author(s):  
Arezoo Zahediasl ◽  
Amin E. Bakhshipour ◽  
Ulrich Dittmer ◽  
Ali Haghighi

In recent years, the concept of a centralized drainage system that connect an entire city to one single treatment plant is increasingly being questioned in terms of the costs, reliability, and environmental impacts. This study introduces an optimization approach based on decentralization in order to develop a cost-effective and sustainable sewage collection system. For this purpose, a new algorithm based on the growing spanning tree algorithm is developed for decentralized layout generation and treatment plant allocation. The trade-off between construction and operation costs, resilience, and the degree of centralization is a multiobjective problem that consists of two subproblems: the layout of the networks and the hydraulic design. The innovative characteristics of the proposed framework are that layout and hydraulic designs are solved simultaneously, three objectives are optimized together, and the entire problem solving process is self-adaptive. The model is then applied to a real case study. The results show that finding an optimum degree of centralization could reduce not only the network’s costs by 17.3%, but could also increase its structural resilience significantly compared to fully centralized networks.


2011 ◽  
Vol 64 (5) ◽  
pp. 1081-1088 ◽  
Author(s):  
Manfred Kleidorfer ◽  
Wolfgang Rauch

The Austrian standard for designing combined sewer overflow (CSO) detention basins introduces the efficiency of the combined sewer overflows as an indicator for CSO pollution. Additionally criteria for the ambient water quality are defined, which comprehend six kinds of impacts. In this paper, the Austrian legal requirements are described and discussed by means of hydrological modelling. This is exemplified with the case study Innsbruck (Austria) including a description for model building and model calibration. Furthermore an example is shown in order to demonstrate how – in this case – the overall system performance could be improved by implementing a cost-effective rearrangement of the storage tanks already available at the inflow of the wastewater treatment plant. However, this guideline also allows more innovative methods for reducing CSO emissions as measures for better usage of storage volume or de-centralised treatment of stormwater runoff because it is based on a sewer system simulation.


Sign in / Sign up

Export Citation Format

Share Document