SPE Membersopyright 1986, Society of Petroleum Engineers rhis paper was prepared for presentation at the 5Sth Califomis Regional Meeting of the Society of Petroleum Engineers held m Oakland, CA, April 24, !9ss, rhis pa~r was selected for presentation by an SPE Program Commmes following review of mlormation contained in an abstract submitted by the suthor(a). Contents of the psper, as presented, have not bean reviewad by the Sosiefy of Petroleum Enginaare and are aubjact to correction by tha guthor(a). The material, aa presented, doas not necessarily reflect any poaifion of the $ociaty of Petroleum Engineers, its offiiere, or members. Papera praaentad at SPE meetings are subject to publication review by Editorial Committees of the Socialy of Petroleum Enginaera. Permission to copy is restricted to an abstract of not more than 200 words, Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where nndby whom the pa~r is presented. Write Publicatiina Manager, SPE, P.O. Sox 83SSSS,FUchardaon, TX 7S0S3-3S3S. Telex, 7309S9, SPEDAL. AbstractIntroduction A new comprehensive model of hydraulic fracturing is presented which has been developed for the Gas Research Institute A substantial amount of effort has been invested, espe-(GRI) mobile fracture monitoring and analysis facility. The cially over the past decade, in the development of models for design and analysis of hydraulic fracturing. The resulting modmain purpose of the model is to simulate the hydraulic fracturing process in real-time, that is on+ite during the fracturing els have varied in at least three major aspects: realism and operation, but the model can also be used for pre-fracture de-generality of the assumptions made in formulating the modsign and post-fracture analysis. Sensor data obtained during ela; complexity of the resulting computer codes and machine the course of the job -requirements; and flexibility of the input-output characteriesuch as wellhead pressure, flow rates, tics, especially in relation to real job conditions and operator frac-fluid viscosity, and proppant staging -can be received . directly by the model se input, superseding the pre-frac job interfacing. Although some good progress haa been made by design schedule, and making possible more accurate model es-many groups, there have not been any models which were satisfactory in all of the three important areas, and most models timatea of current fracturing conditions and predictions of final h fracture geometry, as the job proceeds.ave, at beet, been adequate in one aspect only.The overall model haa four major components describing: Examples of previous work may be found in the consid--flow of fluids and slurry in tubular goods erable literature which has evolved on this subject. The sim-creation and propagation of the hydraulic fracture plest models, assuming 2D geometry with a constant specified -transport of proppant, deposition, and fracture closure height, were those of Christianovich, Geertsma, de Klerk and -heat and fluid exchange between frac...

The character of fluid flow in and around wellbores, cavities, and fractures in para-elastic media can significantly affect resource extraction operations in underground reservoirs. Reasonable estimations of hydraulic fracture profiles and propagation rates cannot be made without considering fluid exchange, especially for high leak-off; well production rates greatly depend on the flow rates into fractures; and reservoir properties are often strongly stress-sensitive.In this paper, the fluid loss and the subsequent "backs tress" (i. e. induced reservoir stress) caused by it are characterized for stationary and propagating fractures, and the model is applied to three cases: 1) a single fluid in the reservoir and fracture; 2) two fluids: a reservoir fluid and a fracture fluid that has penetrated some distance into the reservoir; 3) a production model where the crack has been propped and the reservoir fluid flows out of the well.The fluid exchange between fracture and reservoir is found by solving an integral representation of the flow in the reservoir. Since the pressure distribution in the reservoir is governed by a diffusion process, the flow out of (or into) the fracture and the backstress are rather simply calculated by integrating along the fracture the influcence function for the pressure due to each component of fluid exchange, specifying the pressure at each point on the fracture or closing the system by some other means such as solving simultaneously the flow equations in the fracture, and solving for the fluid exchange inside the integral. Then backs tress can then be found from the fluid exchange. Preliminary computational results for plane fractures have been obtained that compare well with existing special analytical and numerical solutions (e.g., those of Cinco and Samaniego). More general results are provided for moving fractures and induced stresses, and the broader capabilities of the methodology are outlined.References and illustrations at end of paper.

and 1.A. Saiehi, Gas Research Inst. q SPE Members -t l=. &wiity of Petrobum Engineara ThIa paper W08 proaantad a; tha SPS 19SS Imamational Mootingon Petrolaum Enginaaring bald in Saijing, China March 17-20, 1SSS.Tha material is -~~by rho author. Parmisabn to copy is raatrictad!0 an abstract of not mom than SW words. Writ. SPE, P.0, Sox SS3S3S,Richardson, Toxaa~. Tabx 7S0SSS SPE DAL. summaryA new calibre of systems, generically denoted as RT-MACS, has been designed and developed for the monitoring, analysis and potential control of hydraulic fracturing treatments in real-time during the field operation. A number of prototypes have been built, baaed on stateof-the-art computer hardware, ranging fkom super minicomputers to entirely portable systems. They perform the complete spectrum of functions: data-acquisition from calibrated sensors, data-processing and storage in the central facility, display of processed data on scrolling windowa, simulation of the overall process, using realistic engineering models for analysis, and display of overall status, including model reeulk. The models used are unique in many respects: they use real-time data as input; they employ a novel history-matching scheme to determine elusive reservoir and fluid parameters in real-time;and they use the moat advanced threedimensional analysis to make calculations for pressures, height, width~d length of fractures.Both trailertranaported and portable system prototypes have been successfully implemented in a number of commercial field operations, running without disruption in standard jobs on cooperative wells provided by interested producing companies; their presence had sufficient practical impact that the portable systems are now being offered on a broader scale throughout the industry.