Horizontal wells with extended reach drilled in Ghawar field awarded significant improvements, maximizing hydrocarbon production and attained ultimate recoveries. Over the life of those wells, intervention work is necessary to maintain hydrocarbon production by conducting remedial action, such as acid stimulation or water shut off. Necessary data for decision making can be obtained through running surveillance tools, which has proved to be a challenge, considering that these sensors will have to be deployed to total depth (TD). Many well intervention methods have been developed over time to overcome these challenges, such as coiled tubing (CT) and several types of wireline tractors. Wireline tractor technology has evolved to reduce time, cost and improve data quality and increase wellbore coverage. The use of a wireline tractor imposes fewer personnel on the job, much less equipment and less lifting of heavy loads resulting in a smaller footprint impacting the environment. In addition, the fast rig up of the wireline tractor and the running in hole (RIH) and pulling out of hole (POOH) speeds the highly deviated section, and cuts down on operating time. This paper will demonstrate horizontal logging experience gained from trial testing a new deployment solution for the production logging tool (PLT). A new generation of wireline tractors was utilized successfully to deploy the PLT for the first time in the Saudi Arabian field and showed exceptional performance. The tractor proved its capability to overcome different challenging wellbore conditions, such as rugosity, washouts, and high dogleg severity (DLS). Moreover, the tractor was able to efficiently pass through very short sections with large changes in the inclination and azimuth, This paper also covers the whole cycle of candidate selection, job design, execution challenges, post job evaluation, lessons learned and experience gained to optimize similar future jobs.

Saudi Aramco drilling strategy has shifted from vertical to horizontal due to proven advantages in optimizing production and cost. Evaluation of horizontal wells presents new challenges for the industry, especially with increasing water production. Therefore, it is important to determine the flow profile, water entry points and productivity index for remedial action, such as water shut off or selective stimulation. A new generation of production logging tools (PLTs) was introduced and utilized on some horizontal wet producers located in Saudi Arabia. The new PLT is comprised of arrays of spinners and sensors to log the entire cross section to describe precisely the horizontal flow regime. This PLT provides measurements of the downhole production and phases. A comprehensive evaluation was conducted of this type of PLT using different acquisition methodology and deployment methods to understand the best logging procedure. Therefore, one set of the spinners and sensors was attempted into two wells while two sets were attempted in the other two wells. Also, the PLT was deployed using two methods, which are coiled tubing (CT) and wireline tractor. Consequently, a group of lessons learned was gained, and the best logging procedure was established. The operation and interpretation results indicated that the production profiles obtained using this intelligent tool are reliable and accurate. This paper describes cases including planning, deployment, data acquisition, detailed analysis, results and lessons learned. A quality control of the data is also reviewed considering the importance of real time acquisition and validation of the information for future use in reservoir management or well intervention.

Significant drilling challenges can exist when drilling in mature fields or in reservoirs that are subject to various geomechanical stress regimes associated with overpressure, tectonic stress, and depletion. Despite mitigation efforts to reduce stuck-pipe occurrences, drilling problems leading to stuck pipe still occur. When conventional techniques used to free the drillstring are ineffective, wireline logs are often run to determine the stuck depth of the drilling assembly and to release the pipe above the free point.The traditional free-point (FP) logs used to determine the depth of stuck pipe are based on a measurement of strain when stress is applied to the pipe between two points. These measurements are taken at specific intervals and require the tool arms to firmly grip the pipe to prevent movement that could mask the strain measurement. This simple method is difficult to implement reliably. Because it depends on the skill of the specialist operator, pipe-recovery operations include "more art than science." A new technology, based on electromagnetic measurements, can now make a continuous FP log. The log consists of two passes, with and without stress applied to the pipe. By comparing the two responses, service company specialists and drilling engineers can interpret the log without the need for highly-experienced personnel.This paper reviews several cases from the Middle East and provides information about the tool response in various parts of the drilling assembly. It also reviews pipe-recovery techniques that are recommended depending on the FP log response and the specific drilling assemblies, such as drill collar, drill pipe, crossovers, and jars. The pipe-recovery techniques discussed include explosive back-off techniques, explosive pipe severing, and various pipe cutters. The case study examples demonstrate the improved efficiency and reliability of determining stuck-pipe intervals and subsequent successful pipe recovery.

The horizontal wells drilled during the last few years are coming to a mature state in different fields and locations. This has created the requirement to evaluate the performance of the wells and determine water sources for proper reservoir management. In horizontal wells tool deployment, multiple sensor data acquisition and the interpretation of these results is a challenge, particularly when there are long intervals of open hole completions and where fractures are often encountered. The horizontal cased completions use multiple down-hole valves and external packers to provide isolation between intervals. This paper reviews the two primary deployment techniques of coiled tubing and tractor conveyance and highlights their advantages and limitations for each one. In the paper we propose a general guideline for their utilization. The case histories in the paper evaluate the different sensors utilized and provide recommendations particularly for low flow rate conditions. Two interpretation methodologies are evaluated and results are compared along with the interpretation from other sensors. The case studies examples in the paper demonstrate the value of integrating all available information and the value of different data acquisition and evaluation techniques. The conclusions highlight the operational considerations, the data interpretation and added value in the evaluation of well performance to maintain production and improve reservoir management.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Antonio J. Bermudez basin in Southern México is a low porosity massive Jurassic and Cretaceous carbonate reservoir that is extensively faulted and fractured due to post depositional salt intrusions. The natural fractures create many drilling challenges and obstacles. Underbalanced drilling with foam fluid systems has been used to minimize mud losses in these fracture systems. The underbalance drilling, and drilling with casing greatly improves well construction, but these drilling techniques also create many formation evaluation challenges. For example, open hole sonic logs require a liquid filled borehole. Also, formation resistivity is such that lateral logs would be the preferred resistivity device, but they require a conductive borehole fluid.Artificial Neural Network (ANN) methods have traditionally been used for reconstruction of petrophysical data due to tool pulls and poor borehole conditions. Drilling obstacles, in this field, sometimes prohibit the running of conventional open hole logs. Thus, an ANN technique has been developed that uses cased hole pulsed neutron log (PNL) data to synthetically generate a conventional, open hole, triple combo log. These logs are used for well-to-well correlations and for petrophysical evaluation. Still, due to the synthetic smoothing of an ANN result based on casing formation evaluation data (i.e., PNL), detection of natural fractures remains problematic using ANN-based synthetic density data. On the other hand, cased hole dipole sonic anisotropy analysis is routinely used successfully to identify natural fracture systems and far field stress orientation for geomechanical applications. Intervals to be perforated are selected by combining through-casing sonic information with petrophysical analysis of synthetic open hole logs.Data and production results from several wells will be presented and discussed in the paper.