Corporate Office. Innovative Well Intervention Ultra Short Radius (USR) Drilling and Completion Technologies. Effective Reservoir Development

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1 For More Information, please contact: Corporate Office USR DRILLING SERVICES CO, W.L.L Tel: 404 Diplomat Tower Manama, Kingdom of Bahrain Fax: Attn: J. David LaPrade, President d.laprade@usrdrilling.com INDIA INDONESIA D-3132, Oberoi Garden Estates, Chandivili, Andheri (E), Mumbai India Tel : Fax : Menara Thamrin 19th Floor, Suite 1904 Jl. M. H. Thamrin Kav.3 Jakarta Indonesia Tel : Fax : OMAN Way # 5236, Building # 2799 Ghala Sultanate of Oman Tel : / Fax : US Sales Office 600 Kenrick, Suite B-14 Houston, Texas Tel : Fax : MALAYSIA c/o Well Engineering & Technology Sdn Bhd (WellTech) Level 12, Menara Weld, 76, Jalan Raja Chulan, Kuala Lumpur, Malaysia Tel: (603) Fax: (603) USR DRILLING SERVICES CO, W.L.L Innovative Well Intervention Ultra Short Radius (USR) Drilling and Completion Technologies Effective Reservoir Development US Logistics and Support Centre 707 Lehman Street Houston TX Tel: Fax:

2 USR DRILLING SERVICES CO, wll ( USRD ) provides Ultra Short Radius USR Drilling and Completion Technologies. USR is rapidly becoming the preferred choice for a variety of applications, including: Sidetracks from Vertical Wells in Tightly Spaced Fields; Sidetracks from Vertical Wells with Water Coning; Sidetracks from Vertical Wells with Near Wellbore Damage; Sidetracks into Channel Sands with Surrounding Shale; Exploitation of Attic Oil from a Vertical or Horizontal Wells; Exploitation of Low Producing Vertical or Horizontal Wells; Exploitation of Slim Hole Vertical or Horizontal Wells; Sidetracks from Water Injectors to Increase Injection Rates and Improve Sweep Efficiency; To Increase Injectivity and Deliverability in Gas Storage Reservoirs; USR offers the following advantages over conventional horizontal drilling systems: Problem Zones such as Water Sands, Gas Caps and Problematic Shales can be Avoided; Allows a More Efficient Development of Closely Spaced Fields; Downhole Pumps can be Placed at the Top of the Formation to Maximize Productivity; Utilizes Workover Type Rigs, Smaller Pumps and Circulating Systems; Landing in Thin Targets can be more easily achieved when exiting from an existing wellbore and at or near the top of the target formation. Since 1990, our USR teams have been involved in the early testing and development of USR Drilling and Completion Technologies and have drilled more than 200 test wells and more than 250 field applications.

3 WHAT IS ULTRA SHORT RADIUS DRILLING By Definition: Build Up Rate: 100 degrees per 100 feet to 230 degrees per 100 feet Vertical Section of Curve: Minimum 25 feet to a Maximum of 57 feet Long Radius Medium Radius Curve Description Table Description Deg/100 ROC Long 3 to 4 +/ Medium Avg 8 +/ Intermediate Avg 19 +/- 300 Short Max Ultra--Short Max Lateral Lengths Intermediate Radius Short Radius Ultra-Short Radius Description Long Length +/ Medium +/ Intermediate +/ Short +/ Ultra Short +/ Ultra Short Radius Lateral Concept Existing Well Top of Sectioned Casing Cement Plug Radius of Curvature Target Formation Lateral Curve

4 THE USR DRILLING SYSTEMS Rotary Steerable and Mud Motor Drilling has been combined to provide the industry with a unique drilling alternative to conventional horizontal drilling systems. Attributes of the drilling systems employed by USRD include: Ability to re-enter existing wells completed with 4-1/2 OD casing (or larger); Drills a consistent radius of curvature as small as 27 feet; Laterals ranging from 100 to 1,000 can be drilled; Multiple laterals can be drilled from a single well-bore; Compatible with any drilling medium including air, mist and foam; Can be implemented with a drilling rig or service rig; Most horizontal wells are currently drilled with mud motor drilling systems. These mud motor systems are well-suited for drilling medium and long radius curves, but short radius and USR curves (particularly those with less than a 60 radius of curvature) are more difficult and risky. USRD specializes in drilling horizontal wells with radii of feet using a combination of rotary steerable and mud motor assemblies which are specifically designed to achieve high build up rates approaching 230 per 100. Both USRD s drilling systems are specifically designed to be operated from a workover type rig with pipe rotation provided by a top drive power swivel. The use of less costly surface components and smaller location foot print translates to lower drilling costs. One key benefit of USRD s technology is that inclination and azimuth readings are obtained only 2 to 7 from the bit. This reduced projection to the bit distance allows for a planar curve and smoother lateral section. Thin pay zones can be more accurately drilled with less wellpath tortuosity. This provides a definite advantage for well completion and production. NDSC Rig 32 Lekhwair Field, Oman

5 PLANNING, DRILLING and COMPLETING A USR WELL Horizontal drilling has become accepted as a standard option for exploiting oil and gas resources through the re-entry of existing wells and the completion of new ones. The key to successful exploitation of oil and gas reserves is that a targeted property must meet certain criteria to be a good horizontal candidate. For example, the potential prospect must have reservoir or wellbore problems that cannot be solved with vertical holes. Wells experiencing gas or water coning, high pressures and low volumes, or natural fracture systems are potential candidates. Well Planning Well planning begins with selecting the target interval based on the specific objectives of the well and the known reservoir information. The thickness of the target interval, the length of the lateral and the radius of curve to be drilled will determine the kickoff point. A radius of curvature is selected to end the curved section at the point in the reservoir where the lateral is to be initiated. Additional considerations in selecting the radius of curvature include formation properties above the target zone, the type of flexible pipe to be used, casing conditions, and the number of laterals to be drilled. The lateral may be planned as a true horizontal hole or may be planned to traverse the target zone from the top down or the bottom up. The curve is initiated at a predetermined kickoff depth from either a cement plug, whipstock or from formation below the casing shoe. The major steps in a re-entry operation when the target is behind pipe include well preparation, drilling the curve, drilling the lateral and completing the well. Well Preparation Well Preparation is a critical process, and if not done properly, will result in cost overruns, delays and possibly total failure. The two major steps in Well Preparation include the sectioning procedure and cementing of the kickoff plug, followed by the dress off. Sectioning and Under-reaming Procedure Sectioning is the process of removing a section of casing at a predetermined depth to allow the proper radius of curvature to be drilled. The interval to be sectioned depends on the size of the radius and the number of laterals to be drilled. Usually a minimum of 25 is cut to accommodate one 25 to 57 radius. For larger radii and/or multiple curves, a larger section is required. It is important that the sectioned interval be located at the exact depth called for in the well plan. In addition, the section must be circulated clean. There should be no casing or metal remaining in the section interval. If there is any doubt as to the location and/or the quality of the section, the well should be under-reamed and a collar locator log run to verify location and quality. A section not properly located or contaminated with metal could jeopardize the entire re-entry procedure.

6 Whipstock Procedure The preferred method to exit the casing is via whipstock. However, the thickness of the formation and the overlying lithology may not allow use of a whipstock. In many USR applications section milling may be the only option available to avoid overlying shales. Cementing Procedure If the well is to be section milled, a cement plug must be set to provide a base for the kickoff. Following the sectioning and under-reaming procedure, a cement plug is set approximately 20m below the sectioned interval. Cement is then brought up through the sectioned interval and approximately 200 feet inside casing. The cement plug is multi-purpose and must provide: Zone isolation from the original completion. Mechanical strength for the curve drilling assembly to sidetrack. Toughness to remain intact throughout the rotary drilling process and the remaining life of the well. Dress off Procedure Following hours WOC, the plug is dressed to a predetermined depth or Kickoff Point (KOP). In the event dress off commences but cement appears soft, an additional 6-12 hours should be allowed for WOC. Penetration rates should be no less than 2 minutes per foot near the KOP. Wellbore Preparation Schematic Using a Section Mill Section casing from to m and under-ream section out to original hole size of Set Class G cement plug from CIBP up to a minimum depth of 2697m. Operator will dress cement with 8.5 bit to 2765m. KOP m Top of casing window m USRD will drill pilot hole from 2765m to KOP at m with 4.5 PDC bit and Bottom Hole Assembly. CEMENT Section 9 5/8, 69.94KG Casing. Base of casing window m CIBP Set CIBP at 2830m

7 Drilling Procedures The Curve Following a scribing procedure and muleshoe alignment at surface; the Curve Drilling Assembly (CDA) is tripped in the hole to approximately 4 feet from bottom (KOP). Next, a Gyro is run on wireline and stung into the muleshoe. The Gyro orients the CDA to the target direction. A Protractor Plate is used to orient toolface and reference target direction. A Scribe Line is made on the pipe coinciding with target direction on the Protractor Plate. Correction maneuvers are performed to reset the toolface when necessary. In-pipe inclination/azimuth surveys are run periodically to fine tune the end of the curve or departure angle and hole direction. Upon completion of drilling the curve, the CDA is tripped out. The total curve drilling procedure normally requires 8-24 hours, depending on depth, rate of penetration, and radius drilled. The Lateral A Lateral Drilling Assembly (LDA) replaces the CDA to drill the desired horizontal section. Either a USR Mud Motor (USRMM) or a simple Push the Bit (Straight Shooter) assembly is RIH with the required footage of specialty drill pipe. A wet connect system is used to provide survey data while drilling. Completion Options Re-entry Tools for Clean Up A simple and reliable re-entry tool is available for wellbore clean up and stimulation. The tool consists of a simple articulated and jetted sub. This tool provides an effective and low cost option for the re-entry of multi-lateral barefoot USR wells.

8 Completion Options Single Leg Perforated and Slotted Liners can be run through the curve and or lateral. Typically, 2-3/8 8rd. EUE tubing is run in 30 to 40 foot radius curves and 2 7/8 run in larger radii. Articulated and Rotatable Pre-packed Sand Screens Snake Screens have been developed for use in USR wells where screened completions are required. Coiled tubing can be run inside these liners and screens to apply acid or specialty chemical treatments to the lateral. SNAKE SCREENS TM

9 EQUIPMENT REQUIREMENTS The Rig The rig can be a typical service completion unit capable of pulling and racking double stands of pipe. The rig must be in good condition, including the engine, brakes and cables. The floor must be high enough to permit the use of blowout preventers. The weight indicator, power swivel torque gauge and mud pump pressure gauge must be accurate and easily visible on the rig floor. The Power Swivel The power swivel must be the equivalent of a Bowen 2.5 or larger. A remote control panel must be positioned on the rig floor. The power swivel must be electrically or hydraulically controlled, sensitive and respond immediately to the control panel. When placed in the neutral position, the swivel must stop and not continue to rotate. A swivel with a back brake system is preferred. In deeper wells and for longer laterals, a Bowen 3.5 may be required. An accurate torque gauge to monitor drilling torque is required. The Mud Pump The mud pump must be a triplex capable of 110 to 400 gpm and 600 to 2,000 psi. The pump must supply a quiet signal to the pressure gauge at surface. Erratic fluctuation in the signal will make it difficult for the driller to recognize pressure drops during correction maneuvers. The Primary Drill String The primary drill string to be used in the vertical hole must have shouldered connections such IF, AOH, DSS, or PH-6. The pipe must be made up to the manufacturer s make-up torque specification. All inside diameters must be at least 1.9 to pass the gyroscopic orientation tools. The interior of the pipe must be clean and free of all scale and debris. It is recommended that the drill string be drifted, tested, and rattled prior to delivery to the well site. Cross-Overs A full opening of at least 1.9 I.D. is required for all cross-overs. Cross-overs will be needed from the power swivel to the primary string and from the primary string to the USRD UBHO sub (2 3/8 I.F. box).