This paper will aid in sizing, material selection, installation, and operation of atmospheric open bottom mud gas separators (AOBMGS) for onshore well control operations. It is based on a document prepared for the Canadian Petroleum Association (CPA) entitled " Guidelines and Specifications for Designing Mud Gas Separators For Use In the Canadian Drilling Industry".1 Some modifications to the CPA document have been included in this paper.

Electric submersible pumps (ESPs) are a widely used artificial lift technology. Conventional ESP systems provide power with a cable banded to the outside of the tubing. These systems have drawbacks in terms of installation speed and efficiency. To overcome these obstacles, a novel cabledeployed (CD) ESP system developed for use in a high hydrogen sulfide (H2S) production environment is a future solution. This paper focuses on the challenges, results, and lessons learned from the first field deployment in the world of a rigless high H2S, CDESP system. A metal jacketed power cable was a key enabler to the CDESP system. The metal jacketed power cable delivers the best protection for a H2S attack and provides a smooth outside diameter that could be gripped on and sealed. The cable had been tested to withstand H2S levels up to 15% and chloride levels in excess of 150,000 ppm with an expected service life in excess of 10 years. To overcome well control concerns, a vertical cable hanger spool (VCHS) was developed enabling the ESP cable to be terminated below the master valve. In addition to the surface termination of the cable, the VCHS provided hang off and production flow through capabilities. The CDESP system, using a specialized inverted ESP, required close integration between several equipment and service providers during the development of equipment and procedures to ensure success in the installation of the system. The system's initial deployment was in a benign onshore well that offered ample workspace for the various service providers to learn the unique aspects of this rigless deployment. Of particular importance, the interface between the service providers at the surface cable termination was critical to the successful installation. For this trial test, the well completion was changed from 4½-in. tubing to 7-in. tubing to accommodate the cabledeployed 562 series ESP. Lessons learned from this field trial will be incorporated into future trials of the technology. The goal of these future trials will be to deploy the technology in offshore H2S wells where high rig costs can be significantly reduced through the use of lower cost barge coupled with increased speed, efficiency, and ease of CDESP deployment.

Summary Electric submersible pumps (ESPs) are a widely used artificial-lift technology. Conventional ESP systems provide power with a cable banded to the outside of the tubing. These systems have drawbacks in terms of installation speed and efficiency. To overcome these obstacles, a novel cable-deployed (CD) ESP system developed for use in a production environment with high hydrogen sulfide (H2S) content is presented as a future solution. This paper focuses on the challenges, results, and lessons learned from the first field deployment in the world of a rigless high-H2S CD-ESP system. A metal-jacketed power cable was a key enabler to the CD-ESP system. The metal-jacketed power cable delivers the best protection for an H2S attack and provides a smooth outside diameter that could be gripped on and sealed. The cable had been tested to withstand H2S levels up to 15% in the vapor phase and chloride levels in excess of 150,000 ppm, with an expected service life in excess of 10 years, derived from laboratory testing. To overcome well-control concerns, a vertical cable-hanger spool (VCHS) was developed to enable the ESP cable to be terminated below the master valve. In addition to the surface termination of the cable, the VCHS provided hang-off and production-flow-through capabilities. The CD-ESP system, using a specialized inverted ESP, required close integration between several equipment and service providers during the development of equipment and procedures to ensure success in the installation of the system. The system's initial deployment was in a benign onshore well that offered ample workspace for the various service providers to learn the unique aspects of this rigless deployment. The interface between the service providers at the surface-cable termination was critical to the successful installation. For this trial test, the well completion was changed from 4½-in. tubing to 7-in. tubing to accommodate the CD 562 Series ESP. Lessons learned from this field trial will be incorporated into future trials of the technology. The goal of these future trials will be to deploy the technology in offshore H2S wells where high rig costs can be significantly reduced by using a lower-cost barge coupled with increased speed, efficiency, and ease of CD-ESP deployment.

A deviated newly drilled gas well in Western Caspian Sea in Azerbaijan, with a flowing water reservoir pressure of 17,500-psi and a flowing gas reservoir pressure of 12,200-psi was unable to regain flow after an unsuccessful attempt to bullhead produced water back into the well. During the bullheading operation, there was a peak registered pumping pressure of 12,933-psi without admission of fluid into formation. Producing interval was 5880mTVD with a MASP of 9,700-psi for gas reservoir. Coiled Tubing was the most viable option to identify the problem, to solve it and to regain access to the lower completion and then proceed with interval abandonment program. This being an unconventional well in multiple aspects, presented serious challenges accentuated in Safety, Well Integrity Control, Obstruction Removal, and Well Conditioning Plan Forward. Integrity of completion was believed to be compromised by the high pumping pressures applied during bullheading and a confirmed communication between production tubing and "A annulus". After performing 2 rig site visits, an action plan was issued to adjust the platform for a Coiled Tubing intervention for the first time. Points to be developed in the plan were HSE, Structural Analysis and modifications required for proper equipment accommodation. For well integrity control, it was imperative to evaluate the potential scenarios which could have led to the problematic well status. Completion history and specifications were reviewed to assure each of the potential operating scenarios could be controlled without compromising well integrity. On obstruction removal, simulation software was used to design procedure with optimum string, chemicals, rates and fluids to be used for the operation and which contingency fluids considered to be available offshore. It is challenging to perform effective cleanouts in completions with 2 different sizes of tubings (IDs 3.74" & 2.2") combined with restrictions (1.92" nipple), the success is a function of overcoming limited fluid pumping rates, slow annular velocities, particle sizes, cleaning speeds, among others. Well conditioning for future completion operations was planned depending on successful achievements of the coiled tubing intervention. A total of 14 runs with coiled tubing using different BHA configurations were performed to complete the scope. Well was safely and successfully cleaned from a starting depth of 2,512mMD to a target depth of 5,864mMD (5,610mTVD) by removing mud deposits, consolidated sand bridges and completion restrictions. Throughout the cleanout operation, best practices discussed on planning stage were applied to remove multiple obstructions encountered and dealing with potential corkscrewed casing. By accomplishing the well delivery, it is evident that the methodology followed during the planning stage and execution, was crucial to save the well from being lost or abandoned. There was an uncertainty whether the completion integrity was compromised by the high pressures used during the bullheading operation. Novelty in this intervention was the methodology for the risk assessment for an unconventional live well intervention with a 17,500-psi BHP, unseen pressure in the region. Thorough structural analysis was performed to assure the coiled tubing equipment could be placed safely on the platform to condition the well to regain production

No abstract