Success Implementation of Pressurized Mud Cap Drilling in Offshore East Java Prospect, Avoid Rig Flat Time During Loss Circulation and Continue Drilling with 400psi in the Annulus to Reach Target Depth Through Fractured Carbonate Formation in 2 Days

2021 ◽  
Author(s):  
Irawan Fikri ◽  
Ali Ali ◽  
Ismi Airil ◽  
Prasthio Andry ◽  
Setiawan Teguh ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Field Operator ◽  
Control Device ◽  
Drill String ◽  
Lessons Learned ◽  
Carbonate Reservoir ◽  
Total Loss ◽  
Carbonate Formation ◽  
Fractured Carbonate ◽  
Target Depth

Abstract The offshore East Java laid numerous carbonate formation, where depending on area, carbonate formation is exercised as the reservoir. The carbonate exploration drilling campaign, which is naturally fractured, risks the operation not just from safety aspect but also deliverability of well objective to explore uncovered reserve in the area. In this well, total loss circulation was experienced while drilling, despite no record of similar event from offset wells data. The field operator determined to call out Rotating Control Device (RCD) and installed prior to drilling 12.25in. hole section. The Pressurized Mud Cap Drilling (PMCD) method is prepared in advance as mitigation plan to overcome the exploration uncertainties. PMCD is one of the Managed Pressure Drilling (MPD) variants used in oil and gas wells that experience severe to total loss circulation. PMCD method involves drilling with closing flowline valve completely while using RCD system to seal the annulus. While drilling the 12.25in section, absence of return fluid observed as drill string penetrates the carbonate reservoir section (target formation). Activation of the annulus flooding system enables to pumps seawater through annulus, continued with pulling out the string to last casing shoe, and then installation of RCD bearing assembly to convert drilling strategy into PMCD method. As the PMCD components required such as RCD and drill string Non-Return Valve already equipped and all associated procedures prepared in advance, swift transition to PMCD mode results to lesser drilling flat time. After reaching target depth, the PMCD setup also assists in the deployment of open hole logging operation by installing RCD logging adaptor. With the successful PMCD implementation, the field operator managed to reduce drilling risks, reach exploration target successfully, reduce flat times and increase in ROP. This paper present success story of PMCD well drilled and lessons learned as the operator evolves to improve PMCD execution further.

A Novel Approach for Underbalanced Well Completions in Depleted and Highly Fractured Carbonate Reservoirs

2021 ◽  
Author(s):  
Ali Khalid ◽  
Qasim Ashraf ◽  
Khurram Luqman ◽  
Ayoub Hadj-Moussa ◽  
Nasir Hamim
Keyword(s):  
Oil And Gas ◽  
Control Device ◽  
No Production ◽  
Light Weight ◽  
Subject Field ◽  
Underbalanced Drilling ◽  
Novel Approach ◽  
Fractured Carbonate ◽  
The Subject ◽  
Multiphase Fluid

Abstract A prime objective of oil and gas operators is to maximize reservoir productivity and increase the ultimate recovery from all depleting fields. Underbalanced drilling is one such enabling technology that has been adopted world wide to achieve a number of objectives in maximizing the reservoir potential. Chief among these objectives are to reduce formation invasion damage, identify sweet spots in the reservoir, and reduce well costs. Underblanaced operations however introduces more complexity into the successful drilling and completion of a candidate well. An improperly executed underbalanced operation can result in having less productivity in contrast to a conventionally drilled and completed well. Pakistan a country currently highly dependent on foreign hydrocarbon fuels, once had total independence in at least natural gas. The southern part of Pakistan is known for its rich hydrocarbon potential, but most fields were discovered decades ago and have depleted at a rapid pace. Numerous fields in the vicinity have depleted to an extent that the reservoir pressure has reduced to a mere 3.9 PPG in EMW. In the most recently drilled well the pressure depletion caused massive circulation losses while drilling the reservoir formation and the operator had resorted to pumping of heavy LCM pills and blind drilling to complete the section. After completing the well conventionally the operator made multiple attempts to kick off the well but observed no production. Subsequently multiple acid stimulation jobs were performed to reduce the formation damage, but all efforts were in vain. It was evaluated that the heavy LCM and drilled cuttings had bridged off and choked the reservoir skin completely from which there was no return. Ultimately the well had to be plugged and abandoned. In relatively higher pressured and non-fractured formations the option exists to drill a well in underbalanced mode and trip the running string by balancing the well with a light weight fluid. For the subject case however, this option was impossible due to the highly fractured nature of the formation. A plan was devised to include a downhole casing isolation valve in the last casing string and drill the well with an extremely light weight multiphase fluid. A rotating control device would be used to strip the running string in and out of the well. The completion packer was also to be stripped into a live well and set in place without the need of ever killing or balancing the well. By executing the mentioned methodology, the operator was able to drill and complete a well all the while keeping the reservoir formation in a virgin state. The paper discusses the planning, design, execution, and lessons learnt in underbalanced drilling and completion operations in the subject field.

Study on the Construction and Performance of Completion Fluid System in Fractured Carbonate Reservoir

2020 ◽  
Vol 861 ◽  
pp. 388-394
Author(s):  
Cong Bing Chang ◽  
Man Shu ◽  
Yin Fu Han ◽  
Yi Hang Zhang ◽  
Jin Tian ◽  
...  
Keyword(s):  
Early Stage ◽  
Drilling Fluid ◽  
Research Work ◽  
Influence Factors ◽  
Carbonate Reservoir ◽  
Salt Crystallization ◽  
Fluid System ◽  
Carbonate Formation ◽  
Fractured Carbonate ◽  
And Performance

There are microfractures and fractures in the carbonate formation of M oilfield, which are easy to cause collapse and borehole instability. On the basis of the liquefiable cleanflo drilling fluid system for open hole completion of horizontal wells designed in the early stage, this paper has carried out the research work of matching acidizing completion fluid system. In this paper, the influence factors, cleaning ability, compatibility, acidizing situation and protection effect of acidizing completion fluid system are evaluated in laboratory. The way of density adjustment and specific dosage of NaCl and hcoona were established to inhibit the formation of salt crystallization. HTA solid acid and JCI are used to counteract each other to reduce the corrosion of casing steel. The core displacement results show that the permeability recovery value of carbonate core after completion fluid treatment can reach 97.54%, and that of sandstone core after treatment can reach 114.7%. Moreover, the completion fluid system also has a certain acidizing effect, which can not only clean and remove the plugging, but also serve as the early induction of acidizing and stimulation.

Predicting acoustic-wave velocities and fluid sensitivity to elastic properties in fractured carbonate formation

2017 ◽  
Vol 5 (1) ◽  
pp. SB69-SB80 ◽  
Author(s):  
Jingjing Xu ◽  
Maojin Tan ◽  
Xiaochang Wang ◽  
Chunping Wu
Keyword(s):  
Elastic Properties ◽  
Carbonate Rocks ◽  
Seismic Inversion ◽  
Carbonate Reservoir ◽  
S Wave ◽  
Mineral Concentration ◽  
Fracture Porosity ◽  
Wave Velocities ◽  
Carbonate Formation ◽  
Fractured Carbonate

Estimation of S-wave velocity is one of the most critical steps for prestack seismic inversion. Based on the petrophysical model of fractured carbonate rocks, theoretical methods are firstly investigated for estimating P- and S-wave velocities in the presence of fractures. Then, the methods of calculating elastic properties in fractured carbonate rocks are discussed. The mineral concentration, total porosity, and fracture porosity from core X-ray diffraction and routine core measurements or log interpretation results are used to estimate the P- and S-wave velocities. In the given carbonate rock model, the elastic properties of carbonate rocks with different porosity and fractures are calculated. Two field tests prove that the proposed new method is effective and accurate. Furthermore, the model is useful for fluid identification, which is one of the most outstanding problems for carbonate reservoir description. The simulation results suggest that the larger the fracture porosity is, the easier fluid typing. In Tahe Oilfield, the elastic properties of different fluid zones indicate that bulk modulus and Young’s modulus are more sensitive to fluid than shear modulus, the Lamé constant, and Poisson’s ratio.

Lessons Learned from an ESP Development of a Naturally Fractured Carbonate Reservoir Offshore Gabon

2012 ◽  
Author(s):  
Lawrence A.P. Camilleri ◽  
Leila Hamza ◽  
Ozhan Ahmet Yucel ◽  
Vincent Fabien Rodet ◽  
Baptiste Breton
Keyword(s):  
Lessons Learned ◽  
Carbonate Reservoir ◽  
Naturally Fractured ◽  
Fractured Carbonate

Rotating Control Device Sealing Element Customization for Ultra-Deepwater Gulf of Mexico

2021 ◽  
Author(s):  
Blaine Dow ◽  
Dexter Pazziuagan ◽  
Ken Vaczi ◽  
Chima Chima ◽  
Jason Guidry ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Drill Pipe ◽  
Cost Effective ◽  
Control Device ◽  
Drill String ◽  
Lessons Learned ◽  
Test Procedures ◽  
Element Analysis ◽  
Effective Manner ◽  
Tool Joint

Abstract As the Managed Pressure Drilling (MPD) systems for deepwater drilling rigs mature, operators are applying the technology on more complex prospects. Wells are encountering higher pressures in deeper water depths, pushing against the boundaries of technical limits not previously encountered. A prospect in the US Gulf of Mexico required drilling to measured depths exceeding 31000 feet in water deepwater. Under such demanding depth, a non-typical drillstring was required to manage the tensile loading. Typical drill pipe connections on 6 5/8" S-135 tool joints are 8.5" diameter. This drill string would require V-150 landing string, with a 6 5/8" FH tool joint diameter of 8.875". Hard banding would bring the tool joint nominal OD above 9". The depth of the well and planned string RPM presented risk of casing wear, therefore drillpipe protectors would also be required. The depth of the reservoir and size of the drillstring meant pipe would need to be stripped out of the well with up to 900 psi backpressure in order to maintain constant bottom hole pressure. All well challenges were used to determine design specifications for a custom sealing element. The scope of work was to design, validate through finite element analysis, then validate in a test fixture per API16RCD test procedures. On conclusion of the product validation, a land test rig trial, with mock-up of the planned system, including dual sealing elements in the Rotating Control Device (RCD), the required non-rotating drill pipe protectors on the planned drillpipe, was executed. The development schedule from start to finish was compressed to less than 6 months also, targeting completion ahead of the rig's drilling program. This paper will recount the various phases of the design-build-validate-test effort that went into resolving these technical limits. It will conclude with field results and lessons learned from first deployment. As operators pursue more challenging deepwater wells, this systematic approach, through alignment of the operator, drilling contractor and MPD technology company, serves as a model to expand the operating envelope of drilling systems, improving safe performance in a cost-effective manner.

Hybrid Bit Technology Deployment Yields Breakthrough Drilling Performance & Cost Savings for Operator

2021 ◽  
Author(s):  
Fawaz Al-Salah ◽  
Saad Al-Mejmed ◽  
Atef Abdelhamid ◽  
Ali Alnemer ◽  
Tahir Gada ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Impact Damage ◽  
Cost Savings ◽  
Polycrystalline Diamond ◽  
Oil And Gas Industry ◽  
Lessons Learned ◽  
Drill Bit ◽  
Drilling Performance ◽  
Carbonate Formation ◽  
Percent Improvement

Abstract Optimized drilling performance and minimized cost per well are key objectives for operators in the current challenging oil and gas industry. The process of collecting lessons learned and designing new drill bit technologies based on these learnings is critical for optimizing drilling performance and reducing non-productive time (NPT). Southeast Kuwait onshore wells are drilled with conventional drill bit technology such as tungsten carbide insert (TCI) and polycrystalline diamond compact (PDC) bits on rotary or directional-motor bottom hole assemblies (BHA). This paper discusses the analysis that enabled breakthrough-drilling performance of 16-in. hybrid drill bit technology, delivering outstanding results and cost savings for an operator. The non-homogeneous carbonate formation in these onshore wells cause impact damage, limit the drilling efficiency of PDC and TCI bits, and result in a low rate of penetration (ROP) and poor dull conditions. A collaborative technical analysis identified key performance objectives to ensure a step change in section drilling performance. The analysis involved reviewing: Post-run dull conditions Operating parameters Formation compressive strengths Bit design Previous deployments results On Multiple wells, advanced hybrid bit technology and optimized drilling methods achieved outstanding 73-percent improvement in ROP over conventional technologies, saving operator's 3.8 drilling days and more than 27% of drilling costs. The hybrid design completed two consecutive best in class (BIC) wells in southeast Kuwait compared with the typical TCI performance of a single well per bit.

scholarly journals SPECIFICS OF WELL KILLING TECHNOLOGY DURING WELL SERVICE OPERATION IN COMPLICATED CONDITIONS

2020 ◽  
Vol 17 (34) ◽  
pp. 782-792 ◽  
Author(s):  
Dmitry MARDASHOV ◽  
Shamil ISLAMOV ◽  
Yury NEFEDOV
Keyword(s):  
Oil And Gas ◽  
Carbonate Reservoir ◽  
Gas Condensate ◽  
Fluid Loss ◽  
High Hydrogen ◽  
Fractured Carbonate ◽  
Calculation Results ◽  
Single Well ◽  
Hydrogen Sulfide Content ◽  
Ural Province

The process of the well killing operations in the oil and gas condensate field in Volga-Ural province is complicated due to several conditions like fractured carbonate reservoir, abnormally low reservoir pressure, high gas-oil ratio, high hydrogen sulfide content, acid fracturing, and hydrochloric acid treatments requirement. During the well killing process, significant gas breakthroughs and fluid loss are observed in this field, which requires significant usage of blocking compositions (up to 50-100 m3 per single well) and increases the well service costs. The aim of this work was to increase the well killing efficiency during well service by studying the mechanisms that take place near the wellbore zone during this process. The application of statistical and multifactor analysis of well-killing processes were conducted from 2018 to 2019, which allowed highlighting the main reasons for the low success of these works. The calculation results showed that the stress state near the well significantly differs from the regional stress field and varies depending on the generated pressure in the well, which in turn affects the activity of fractures near the wellbore. The revealed mechanisms that take place near the wellbore zone coupled with the laboratory and pilot tests of the blocking compositions can be used to improve the well service operations at the oil and gas condensate field in the Volga-Ural province. In this work, it was concluded that it is important to use the geomechanical approach to increase the well killing efficiency in combination with a complex of laboratory rheological and filtration tests of blocking compositions.

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