Development and First Application of an Ultra-Low Density Non-Aqueous Reservoir Drilling Fluid in the United Arab Emirates: A Viable Technical Solution to Drill Maximum Reservoir Contact Wells Across Depleted Reservoirs

2021 ◽  
Author(s):  
Ramanujan Jeughale ◽  
Kerron Andrews ◽  
Salim Abdalla Al Ali ◽  
Takahiro Toki ◽  
Hisaya Tanaka ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Drilling Fluid ◽  
Surface Condition ◽  
Field Application ◽  
Lessons Learned ◽  
Technical Solution ◽  
Low Density ◽  
Reservoir Water ◽  
Laboratory Test Results ◽  
Organophilic Clay

Abstract Drilling and completion operations in depleted reservoirs, are challenging due to narrow margin between pore and fracture pressures. Therefore, Ultra-Low Density Reservoir Drilling Fluid (RDF) with optimum parameters is required to drill these wells safely. Design and effective field application of a sound engineered fluid solution to fulfill these operational demands are described. Ultra-Low Density RDF NAF with minimal fluid invasion characteristics was developed after extensive lab testing, to cover the fluid density from 7.2 – 8.0 ppg. The fluid properties were optimized based on reservoir requirements and challenging bottom-hole conditions. The design criteria benchmarks and field application details are presented. Fluids were stress tested for drill solids, reservoir water and density increase contamination. Multi-segment collaboration and teamwork were key during job planning and on-site job execution, to achieve operational success. For the first time in UAE, a major Offshore Operator successfully applied an Ultra-Low Density RDF-NAF, which provided remarkable stability and performance. The fluid was tested in the lab with polymeric viscosifier alone and in combination with organophilic clay. In order to gain rheology during the initial mixing, about 3.0 ppb of organophilic clay were introduced to system along with the polymeric viscosifier. Later, all the new fluid batches were built with polymeric additives alone to achieve target properties. A total of 10,250 ft of 8 ½" horizontal section was drilled to section TD with record ROP compared to previous wells in the same field, with no fluids related complications. With limited support from the solid control equipment, the team managed to keep the density ranging from 7.5 ppg to 7.8 ppg at surface condition, using premixed dilution. Bridging was monitored through actual testing on location and successfully maintained the target PSD values throughout the section by splitting the flow on three shaker screen size combination. Due to non-operation related issues, hole was kept static for 20 days. After such long static time, 8 ½" drilling BHA was run to bottom smoothly precautionary breaking circulation every 5 stands. Finally, after successful logging operation, 6 5/8" LEL liner was set to TD and the well completed as planned. Success of this field application indicates that an Ultra-Low density fluid can be designed, run successfully and deliver exemplary performance. Lessons learned are compared with conceptual design for future optimization. Laboratory test results are presented, which formed the basis of a seamless planned field application.

Innovative Washpipe Free Circulating ICD Delivers Reduced Well Construction Costs

2021 ◽  
Author(s):  
Zhihua Wang ◽  
Daniel Newton ◽  
Aqib Qureshi ◽  
Yoshito Uchiyama ◽  
Georgina Corona ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Drilling Fluid ◽  
Aqueous Fluid ◽  
Control Device ◽  
Lessons Learned ◽  
Innovative Technology ◽  
Well Performance ◽  
Construction Costs ◽  
Inflow Control Device ◽  
Testing Field

Abstract This Extended Reach Drilling (ERD) field re-development of a giant offshore field in the United Arab Emirates (UAE) requires in most cases extremely long laterals to reach the defined reservoir targets. However, certain areas of the field show permeability and / or pressure variations along the horizontal laterals. This heterogeneity requires an inflow control device (ICD) lower completion liner to deliver the required well performance that will adequately produce and sweep the reservoir. The ICD lower completion along with the extremely long laterals means significant time is spent switching the well from reservoir drilling fluid (RDF) non-aqueous fluid (NAF) to an aqueous completion brine. To reduce the amount of rig time spent on the displacement portion of the completion phase, an innovative technology was developed to enable the ICDs to be run in hole in a closed position and enable circulating through the end of the liner. The technology uses a dissolvable material, which is installed in the ICD to temporarily plug it. The dissolvable material is inert to the RDF NAF while the ICDs are run into hole, and then dissolves in brine after the well is displaced from RDF NAF to completion brine, changing the ICDs from closed to an open position. The ability to circulate through the end of the liner, with the support of the plugged ICDs, when the lower completion is deployed and at total depth (TD), enables switching the well from RDF NAF drilling fluid to an aqueous completion brine without the associated rig time of the original displacement method. The technique eliminates the use of a dedicated inner displacement string and allows for the displacement to be performed with the liner running string, saving 4-5 days per well. An added bonus is that the unique design allowed for this feature to be retrofitted to existing standard ICDs providing improved inventory control. In this paper the authors will demonstrate the technology and system developed to perform this operation, as well as the qualification testing, field installations, and lessons learned that were required to take this solution from concept to successful performance improvement initiative.

Hollow Glass Spheres HGS in Drilling Fluid: Case Study of Preventing and Mitigating Total Losses

2021 ◽  
Author(s):  
Vitaly Sherishorin ◽  
Martin Rylance ◽  
Yevgeniy Tuzov ◽  
Olga Krokhaleva ◽  
Evgeny Tikhonov ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Scale Up ◽  
Cost Savings ◽  
Field Application ◽  
Lessons Learned ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
Initial Application ◽  
General Plan ◽  
Effective Manner

Abstract The paper describes the first deployment of HGS in Eastern Siberia as a mud additive. The technology was utilized for reducing drilling fluid density for prevention and mitigation of losses; while drilling through a producing reservoir section with low pore pressure, unconsolidated and fractured sands. The engineering considerations, fundamentals of the approach and major risks involved were reviewed with application to the Sredneboutobinskoye Oilfield as a pilot field application for broader future plans. Key planning, delivery and execution principles of the initial application will be reported in the paper. Initially deployed on three wells, including multi-laterals (Rylance et al., 2021), the paper will walk through the engineering considerations during the planning and execution phases. Key sections include the data gathered and the many lessons learned during the incremental and stepwise deployment. The paper will also report on post drilling productivity and comparisons with the offset wells drilled with conventional mud systems, which suffered severe losses. The results of this pilot have exceeded expectations. There have been many insights and the Team are now looking to set a timetable to scale-up across the Taas-Yuryakh Neftegazodobycha (TYNGD). After many hours of laboratories study and preparation works, the general plan was to reduce the static density and ECD to mitigate fluid losses. However, the applied results showed additional effects from HGS. Data will be provided that demonstrated loss-free drilling was achieved where this had not been the case before, with a material reduction in NPT, lost circulation material (LCM) needs and costs. Much has been learned, recovered HGS material has been demonstrated to be an effective LCM pill and centralization of mud processing may offer additional cost savings and improvements. Further efficiencies are also expected to be achieved and future potential is considerable. HGS for cementing is well documented, yet application for drilling fluids has been less well reported and almost exclusively related to single wells. The TYNGD application is innovative as this is a major development with 10 active drilling rigs. The application is on multi-laterals and offset wells are available for direct comparison. The results of the approach demonstrate a new way of performing well construction in an effective manner for major field developments where losses are prevalent.

Successful Application of a New Generation of Clay Inhibitor Polymers While Drilling a Deep Exploration Well in the Astrakhan Region

2021 ◽  
Author(s):  
Petr Leonidovich Ryabtsev ◽  
Sergey Viktorovich Popov ◽  
Andrey Vladimirovich Korolev ◽  
Samat Maratovich Urakov ◽  
Andrey Aleksandrovich Akvilev
Keyword(s):  
Drilling Fluid ◽  
Cost Effective ◽  
Field Application ◽  
The Body ◽  
Gas Condensate ◽  
Laboratory Test Results ◽  
Geological Conditions ◽  
New Generation ◽  
Exploration Well ◽  
Polymer Type

Abstract This paper presents the results of laboratory studies and field application of a drilling fluid based on a new generation of polymer inhibitors. The summarized results of the application confirm the effectiveness of the new polymer type used. The body of the article is devoted to the experience of using an innovative drilling fluid system for drilling an exploration well in the Astrakhan gas condensate field. One of the features of the Astrakhan gas condensate field is a number of intervals of possible complications: lost circulation zones, prone to clay swelling and caving, and presence of salts and hydrogen sulfide in the reservoir. One of the solutions for ensuring trouble-free drilling in such conditions is using an oil-based drilling fluid (OBM). However, OBM is often avoided when drilling exploratory wells due to environmental and technological limitations. In this connection, the project team carried out work on selection and development of a water-based drilling fluid formulation, which would ensure the most trouble-free and cost-effective drilling operations. Considering these studies, a drilling fluid was selected based on a new generation of inhibitor polymers. The key feature of the proposed formulation is the use of a new polar inhibitor polymer. The selected formulation showed the best laboratory test results after which it was approved for application. The main risk of using the new drilling fluid formulation was lack of filed experience in using this system in similar geological conditions. At the same time, laboratory tests showed that the proposed alternative mud formulations did not provide the required level of contamination resistance and inhibiting ability. Over the period from April to September of 2020, the exploration well was successfully drilled at the Astrakhan gas condensate field using the selected drilling fluid based on a new polymer type. Using the same drilling fluid type, four intervals - from the surface pipe to the production liner, - were drilled.

MODELING OF THE DYNAMIC PROCESS RELEASE OF STUCK DRILLING TOOLS BY HYDRO-PULSE METHOD

2019 ◽  
pp. 94-103
Author(s):  
K. H. Levchyk ◽  
M. V. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Dynamic Process ◽  
Drilling Fluid ◽  
Pulse Method ◽  
Geometrical Parameters ◽  
Technical Solution ◽  
Rock Layer ◽  
Drilling Tool ◽  
Drilling Tools ◽  
Drill Pipes

A technical solution is proposed for the elimination the grabbing of drilling tool, based on the use of energy due to the circulation of the drilling fluid. The expediency eliminating the grabbing drilling tool using the hydro-impulse method is substantiated. A method of drawing up a mathematical model for the dynamic process of a grabbing string of drill pipes in the case of perturbation of hydro-impulse oscillations in the area of the productive rock layer is developed. The law of longitudinal displacements arising in the trapped string is obtained, which allows choosing the optimal geometrical parameters of the passage channels and the frequency rotational of shutter for these channels. Recommendations for using this method for practical use have been systematized.

A multicenter prospective hospital-based cohort study on the efficacy and safety of pitavastatin.

2020 ◽  
Vol 17 ◽  
Author(s):  
Abdullah Shehab ◽  
Asim Ahmed Elnour ◽  
Akshaya Srikanth Bhagavathula ◽  
Joseph Pulavelil Kurian ◽  
Gazi Hassan ◽  
...  
Keyword(s):  
Cohort Study ◽  
Adverse Events ◽  
United Arab Emirates ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Efficacy And Safety ◽  
Onset Diabetes ◽  
The Mean ◽  
New Onset

Aims: We aim to investigate the efficacy and safety of pitavastatin 4 mg in a population of people living in the United Arab Emirates (UAE). Background: Pitavastatin is a member of the HMG-CoA reductase inhibitors family which was approved for use in adult subjects with primary hyperlipidemia or mixed dyslipidemia. To date, no published studies have assessed the efficacy and safety of pitavastatin in the United Arab Emirates. Objective: The main objective of the current study was to investigate the efficacy and safety of pitavastatin in subjects with dyslipidemia for primary prevention of cardiovascular diseases based on total cardiovascular risk. Methods: This was a multicentre (four private hospitals) prospective cohort study to analyze data on the use of pitavastatin for dyslipidemia in adult outpatients in Abu Dhabi and Dubai emirates, United Arab Emirates. We have followed-up the clinical profiles of subjects in four hospitals for six-weeks during the period from June 2015 to June 2017. Efficacy was based on the evaluation of the mean (± standard deviation) change in low-density lipoprotein cholesterol between baseline and week six after the initiation of pitavastatin therapy. Safety was reported as the incidence of adverse events occurred with the use of pitavastatin and the development of new-onset diabetes. Results: A total of 400 subjects who were receiving pitavastatin 4 mg were included. The mean age of subjects was 50.7 ±10.8 years, of these 79.0% were males. At the baseline, the mean level of total cholesterol was 185.4 ±41.5 mg/dL, low density lipoprotein was 154.9 ±48.55 mg/dL, high-density lipoprotein cholesterol was 40.5 ±11.23 mg/dL and fasting blood glucose was 115.0 (±16.63) mg/dl. At the end of six weeks, low density lipoprotein levels significantly decreased to 112.09 ±41.90 mg/dl (standard mean difference [SMD] (-42.8%), 95% CI: -42.88 [-49.17 to -36.58] mg/dl, P <0.001), while high density lipoprotein levels improved (SMD, 95% CI: 1.77% [0.25 to 3.28] mg/dl, P <0.022). There were 55 subjects (13.7%) reported various adverse events such as myalgia (7.5%), sleep disorders (2.5%), and myopathy (2.2%). Furthermore, 4 (1.0%) have had developed new-onset diabetes post six-weeks of initiation of pitavastatin therapy. Conclusion: Pitavastatin 4 mg had howed robust efficacy in reducing LDL-C levels and improving HDL-C levels in subjects with dyslipidemias. The use of pitavastatin was associated with a low discontinuation rate, fewer adverse events, and very limited cases of new-onset diabetes.

Evaluation and Optimization of Low-Density Cement: Laboratory Studies and Field Application

2010 ◽  
Vol 25 (01) ◽  
pp. 70-89 ◽  
Author(s):  
Abdullah S. Al-Yami ◽  
Hisham A. Nasr-El-Din ◽  
Ahmad S. Al-Humaidi ◽  
Salah H. Al-Saleh ◽  
Mohammed K. Al-Arfaj
Keyword(s):  
Field Application ◽  
Low Density ◽  
Laboratory Studies

A Generalized Model for the Field Assessment of Drilling Fluid Viscoelasticity

2021 ◽  
Author(s):  
Chen Hongbo ◽  
Okesanya Temi ◽  
Kuru Ergun ◽  
Heath Garett ◽  
Hadley Dylan
Keyword(s):  
Drilling Fluid ◽  
Field Testing ◽  
Field Application ◽  
Testing Equipment ◽  
Drilling Fluids ◽  
Rotational Viscometer ◽  
Generalized Model ◽  
Fluid Elasticity ◽  
Field Samples ◽  
Drilling Operations

Abstract Recent studies highlight the significant role of drilling fluid elasticity in particle suspension and hole cleaning during drilling operations. Traditional methods to quantify fluid elasticity require the use of advanced rheometers not suitable for field application. The main objectives of the study were to develop a generalized model for determining viscoelasticity of a drilling fluid using standard field-testing equipment, investigate the factors influencing drilling fluid viscoelasticity in the field, and provide an understanding of the viscoelasticity concept. Over 80 fluid formulations used in this study included field samples of oil-based drilling fluids as well as laboratory samples formulated with bentonite and other polymers such as partially-hydrolyzed polyacrylamide, synthesized xanthan gum, and polyacrylic acid. Detailed rheological characterizations of these fluids used a funnel viscometer and a rotational viscometer. Elastic properties of the drilling fluids (quantified in terms of the energy required to cause an irreversible deformation in the fluid's structure) were obtained from oscillatory tests conducted using a cone-and-plate type rheometer. Using an empirical approach, a non-iterative model for quantifying elasticity correlated test results from a funnel viscometer and a rotational viscometer. The generalized model was able to predict the elasticity of drilling fluids with a mean absolute error of 5.75%. In addition, the model offers practical versatility by requiring only standard drilling fluid testing equipment to predict viscoelasticity. Experimental results showed that non-aqueous fluid (NAF) viscoelasticity is inversely proportional to the oil-water ratio and the presence of clay greatly debilitates the elasticity of the samples while enhancing their viscosity. The work efforts present a model for estimating drilling fluid elasticity using standard drilling fluid field-testing equipment. Furthermore, a revised approach helps to describe the viscoelastic property of a fluid that involves quantifying the amount of energy required to irreversibly deform a unit volume of viscoelastic fluid. The methodology, combined with the explanation of the viscoelasticity concept, provides a practical tool for optimizing drilling operations based on the viscoelasticity of drilling fluids.

Case History: Coring in ERD Well with Collision Risk Challenge and Optimization of Coring Parameters Based on Previous Coring Jobs in Carbonate Formation Alleviated Core Recovery

2021 ◽  
Author(s):  
Rahul Kamble ◽  
Youssef Ali Kassem ◽  
Kshudiram Indulkar ◽  
Kieran Price ◽  
Majid Mohammed A. ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Lessons Learned ◽  
Low Flow ◽  
High Angle ◽  
Collision Risk ◽  
Pilot Hole ◽  
Field Development ◽  
Core Recovery ◽  
Carbonate Formation ◽  
Carbonate Formations

Abstract Coring during the development phase of an oil and gas field is very costly; however, the subsurface insights are indispensable for a Field Development Team to study reservoir characterization and well placement strategy in Carbonate formations (Dolomite and limestone with Anhydrite layers). The objective of this case study is to capture the successful coring operation in high angle ERD wells, drilled from the fixed well location on a well pad of an artificial island located offshore in the United Arab Emirates. The well was planned and drilled at the midpoint of the development drilling campaign, which presented a major challenge of wellbore collision risk whilst coring in an already congested area. The final agreed pilot hole profile was designed to pass through two adjacent oil producer wells separated by a geological barrier, however, the actual separation ratio was &lt; 1.6 (acceptable SF to drill the well safely), which could have compromised the planned core interval against the Field Development Team's requirement. To mitigate the collision risks with offset wells during the coring operation, a low flow rate MWD tool was incorporated in the coring BHA to monitor the well path while cutting the core. After taking surveys, IFR and MSA corrections were applied to MWD surveys, which demonstrated an acceptable increase in well separation factor as per company Anti-Collision Risk Policy to continue coring operations without shutting down adjacent wells. A total of 3 runs incorporating the MWD tool in the coring BHA were performed out of a total of 16 runs. The maximum inclination through the coring interval was 73° with medium well departure criteria. The main objective of the pilot hole was data gathering, which included a full suite of open hole logging, seismic and core cut across the target reservoir. A total of 1295 ft of core was recovered in a high angle well across the carbonate formation's different layers, with an average of 99% recovery in each run. These carbonate formations contain between 2-4% H2S and exhibit some fractured layers of rock. To limit and validate the high cost of coring operations in addition to core quality in the development phase, it was necessary to avoid early core jamming in the dolomite, limestone and anhydrite layers, based on previous coring runs in the field. Core jamming leads to early termination of the coring run and results in the loss of a valuable source of information from the cut core column in the barrel. Furthermore, it would have a major impact on coring KPIs, consequently compromising coring and well objectives. Premature core jamming and less-than-planned core recovery from previous cored wells challenged and a motivated the team to review complete field data and lessons learned from cored offset wells. Several coring systems were evaluated and finally, one coring system was accepted based on core quality as being the primary KPI. These lessons learned were used for optimizing certain coring tools technical improvements and procedures, such as core barrel, core head, core handling and surface core processing in addition to the design of drilling fluids and well path. The selection of a 4" core barrel and the improved core head design with optimized blade profile and hold on sharp polished cutters with optimized hydraulic efficiency, in addition to the close monitoring of coring parameters, played a significant role in improving core cutting in fractured carbonate formation layers. This optimization helped the team to successfully complete the 1st high angle coring operation offshore in the United Arab Emirates. This case study shares the value of offset wells data for coring jobs to reduce the risk of core jamming, optimize core recovery and reduce wellbore collision risks. It also details BHA design decisions(4"core barrel, core head, low flow rate MWD tool and appropriate coring parameters), all of which led to a new record of cutting 1295 ft core in a carbonate formation with almost 100% recovery on surface.

Stimulation of Wells Damaged by Barite Present in Filter Cake or Scale

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Igor Ivanishin ◽  
Hisham A. Nasr-El-Din ◽  
Dmitriy Solnyshkin ◽  
Artem Klyubin
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Ethylenediaminetetraacetic Acid ◽  
Solid Phase ◽  
Barium Carbonate ◽  
Process Analysis ◽  
Drilling Fluid ◽  
Field Application ◽  
X Ray ◽  
Dissolution Efficiency

Summary High-temperature (HT) deep carbonate reservoirs are typically drilled using barite (BaSO4) as a weighting material. Primary production in these tight reservoirs comes from the network of natural fractures, which are damaged by the invasion of mud filtrate during drilling operations. For this study, weighting material and drilling fluid were sampled at the same drillsite. X-ray diffraction (XRD) and X-ray fluorescence analyses confirmed the complex composition of the weighting material: 43.2 ± 3.8 wt% of BaSO4 and 47.8 ± 3.3 wt% of calcite (CaCO3); quartz and illite comprised the rest. The drilling fluid was used to form the filter cake in a high-pressure/high-temperature (HP/HT) filter-press apparatus at a temperature of 300°F and differential pressure of 500 psig. Compared with the weighting material, the filter cake contained less CaCO3, but more nondissolvable minerals, including quartz, illite, and kaolinite. This difference in mineral composition makes the filter cake more difficult to remove. Dissolution of laboratory-grade BaSO4, the field sample of the weighting material, and drilling-fluid filter cake were studied at 300°F and 1,000 to 1,050 psig using an autoclave equipped with a magnetic stirrer drive. Two independent techniques were used to investigate the dissolution process: analysis of the withdrawn-fluid samples using inductively coupled plasma-optical emission spectroscopy, and XRD analysis of the solid material left after the tests. The dissolution efficiency of commercial K5-diethylenetriaminepentaacetic acid (DTPA), two K4-ethylenediaminetetraacetic acid (EDTA), Na4-EDTA solutions, and two “barite dissolvers” of unknown composition was compared. K5-DTPA and K4-EDTA have similar efficiency in dissolving BaSO4 as a laboratory-grade chemical and a component of the calcite-containing weighting material. No pronounced dissolution-selectivity effect (i.e., preferential dissolution of CaCO3) was noted during the 6-hour dissolution tests with both solutions. Reported for the first time is the precipitation of barium carbonate (BaCO3) when a mixture of BaSO4 and CaCO3 is dissolved in DTPA or EDTA solutions. BaCO3 composes up to 30 wt% of the solid phase at the end of the 6-hour reaction, and can be dissolved during the field operations by 5 wt% hydrochloric acid. Being cheaper, K4-EDTA is the preferable stimulation fluid. Dilution of this chelate increases its dissolution efficiency. Compared with commonly recommended solutions of 0.5 to 0.6 M, a more dilute solution is suggested here for field application. The polymer breaker and K4-EDTA solution are incompatible; therefore, the damage should be removed in two stages if the polymer breaker is used.

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